Color filter, method of fabricating the same and liquid-crystal display device

ABSTRACT

A color filter having two-layered light-shielding sections without a black matrix is provided, which reduces the level difference from the colored materials for pixels with a simple method and makes it possible to remove the color layer on the said sections. A red color layer having stripe-shaped red pixel formation sections and a blue color layer having stripe-shaped blue pixel formation sections are overlapped to form two-layered light-shielding sections. A green color layer having island-shaped green pixel formation sections is overlapped with the red and blue color layers, placing the green pixel formation sections in the overlapped green pixel windows of the red and blue color layers. Only the peripheries of the green pixel formation sections are placed on the light-shielding sections to facilitate the removal of the peripheries by polishing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a color filter and more particularly,to a color filter whose light-shielding sections are formed byoverlapping two different color layers without using a black matrix, amethod of fabricating the color filter, and a Liquid-Crystal Display(LCD) device using the said color filter.

The present invention is applicable to not only LCD devices of varioustypes but also any other devices using a color filter, such asfield-emission type display devices, vacuum fluorescent display devices,plasma display devices and image pickup devices.

2. Description of the Related Art

Conventionally, the color filter used for LCD devices comprises coloredmaterials of red (R), blue (B) and green (G) arranged in the respectiveopenings for the pixels to have a predetermined layout (e.g., mosaic,stripe, or delta layout), and a patterned black matrix (which is made ofblack resin or metal oxide) formed in the light-shielding sections otherthan the openings. The main reason why the black matrix is used is toraise the contrast, to prevent the mixture among the red, blue, andgreen colored materials, and to shield the light toward thesemiconductor films of the TFTs (Thin-Film Transistors).

With the LCD devices for cellular phones and small-sized LCD devices,essential contrast is not so high. Therefore, no black matrix is used;alternatively, light-shielding sections are formed by partiallyoverlapping the colored materials located in the adjoining openings torealize a light-shielding function similar to that of the black matrix.This is because there is an advantage that the materials, process stepsand fabrication cost are reduced since the black matrix is not used.

On the other hand, with the LCD devices for display monitors forpersonal computers or televisions (TVs), high contrast is essential.Therefore, to omit the black matrix, a structure having an equivalentlight-shielding function to that of the black matrix is required.However, if an equivalent light-shielding function to that of the blackmatrix is obtained by overlapping the colored materials located in theadjoining openings in the typical color filter including coloredmaterials of three primary colors (i.e., red, blue and green), thelight-shielding performance of the overlapped parts (stacked parts) ofthe red and green colored materials is lower than that of the overlappedparts of the other colored materials. This means that the backlight isunable to be shielded sufficiently. For this reason, various ideas haveever been presented and announced to solve this problem.

For example, the Japanese Non-Examined Patent Publication No. 2000-29014discloses a color filter substrate, which realizes the light-shieldingfunction in the frame area that surrounds the effective display regionwithout the black matrix. With this color filter substrate, threecolored layers of red, green and blue are formed in the effectivedisplay region and at the same time, two or three of the red, green andblue colored layers are overlapped to form the light-shielding layers inthe frame area. In the Publication No. 2000-29014, it is said that thered and blue colored layers are preferably overlapped to realize thelight-shielding function. This is because when the red and blue coloredlayers are overlapped with each other, its transmittance of light can belowered compared with the areas where the green and blue colored layersare overlapped or the red and green ones are overlapped. In addition, itis said in the Publication No. 2000-29014 that the inter-pixel shieldingof light in the effective display region is conducted by overlapping thered and green colored layers, the green and blue colored layers, or theblue and red colored layers (See claims 1 to 2 and FIG. 1).

Therefore, with the color filter substrate of the Publication No.2000-29014, the inter-pixel light-shielding sections in the effectivedisplay region have a two-layer structure of two adjacent ones of thered, blue, and green colored layers. On the other hand, thelight-shielding sections in the frame area have a three-layer structureof the red, blue, and green colored layers or a two-layer structure oftwo adjacent ones thereof.

The Japanese Non-Examined Utility-Model Publication No. 62-181927discloses a color LCD device, where color images are displayed withthree primary colors (i.e., red, green and blue) while the backgroundregion is made black. The feature of this device is as follows: Threecolor filters are provided to realize three primary colors on differentsurfaces of the substrate and polarizer. One of these color filters isformed on the whole surface for a display color and the two remainingcolor filters are formed in the background region alone. The backgroundregion is made black with a three-layer structure of the three colorfilters overlapped (See claim 1 and FIG. 1).

With the LCD device of the Publication No. 62-181927, since thebackground region to be made black is constituted by the three-layerstructure of the three primary color filters, the inter-pixellight-shielding sections have a three-layer structure of the said colorfilters.

The Japanese Patent No. 2590858 (which corresponds to the JapaneseNon-Examined Patent Publication No. 63-187277) discloses a color filter,which comprises colored patterns of red, green and blue, and blackpatterns, all of which are arranged on a transparent support. The blackpatterns, which are placed in the peripheral area of the screen, areformed by overlapping the three colored layers of red, green and blue,or the two colored layers thereof. The feature of this color filter isas follows: In the boundary and adjacent areas of the respective coloredpatterns of red, green and blue, the black patterns are formed byoverlapping the three colored layers of red, green and blue. On theother hand, in the peripheral area of the screen, the black patterns areformed by overlapping the two colored layers of red and blue (See claim1 and FIGS. 1 to 4).

Therefore, with the color filter of the U.S. Pat. No. 2,590,858, theinter-pixel light-shielding sections in the display region have athree-layer structure of the red, blue, and green colored layers, andthe frame area is formed by a two-layer structure of red and bluecolored layers.

The Japanese Non-Examined Patent Publication No. 08-095021 discloses amethod of fabricating a color filter, where the black matrix layer isformed by overlapping the transparent colored layers during the processof forming the respective colored layers to obtain a color filter withgood flatness. The feature of this method is as follows: Thethree-layered black matrix layer is formed by using a photomask withhalf-tone masking regions corresponding to the light-shielding sectionsat the same time as the formation of the three colored layers of red,green and blue (See claim 1 and FIGS. 1 to 2).

With the color filter fabricated by the method of the Publication No.08-095021, both the inter-pixel light-shielding sections in the displayregion and the light-shielding sections in the frame area have athree-layer structure of the red, blue, and green colored layers.

The Japanese Non-Examined Patent Publication No. 2003-014917 disclosesthree color filters as follows (See claims 1 to 3 and FIGS. 1 to 2).

(i) A first one of the color filters comprises pixels formed andarranged by colored layers on a transparent substrate, where the framearea, which is located in the periphery of the display region, is formedby at least two ones of the colored layers. The feature of this colorfilter is that the red colored layer has an average transmittance of 1%or less in the wavelength region of 460 to 570 nm.

(ii) A second one of the color filters comprises pixels formed andarranged by colored layers on a transparent substrate, where the framearea is formed by at least two ones of the colored layers. The featureof this color filter is that the blue colored layer has an averagetransmittance of 1% or less in the wavelength region of 560 to 750 nm.

(iii) A third one of the color filters comprises pixels formed andarranged by colored layers on a transparent substrate, where the framearea is formed by at least two ones of the colored layers. The featureof this color filter is that each of the red and blue colored layers hasan average transmittance of 2.5% or less in the wavelength region of 555to 575 nm.

In the Publication No. 2003-014917, it is said that high OD (OpticalDensity) values can be obtained by only the stacked or overlappedstructure of the colored layers in the frame area and thelight-shielding sections opposite to the TFTs. With these filters, theframe area, the inter-pixel light-shielding sections, and thelight-shielding sections opposite to the TFTs are formed by athree-layer structure of the red, blue, and green colored layers, or atwo-layer structure thereof.

The Japanese Non-Examined Patent Publication No. 2002-082630 disclosestwo electrooptic devices as follows (See claims 1 to 2 and FIGS. 1 to2):

(i) A first one of the electrooptic devices comprises TFTs, andlight-shielding sections formed by overlapping a first colored layer anda second colored layer, wherein the light-shielding sections areoverlapped with at least the channel formation regions of the TFTs.

(ii) A second one of the electrooptic devices comprises pixelelectrodes, and light-shielding sections formed by overlapping a firstcolored layer and a second colored layer, wherein the light-shieldingsections are by overlapped with the intervening areas between one of thepixel electrodes and another adjacent thereto.

In the Publication No. 2002-082630, it is said that the first coloredlayer is preferably blue and the second colored layer is preferably red.With these two electrooptic devices, the light-shielding sectionscorresponding to the channel formation regions of the TFTs or theinter-pixel light-shielding sections have a two-layer structure formedby two of the red, blue, and green colored layers.

As described above, various ideas have ever been presented and announcedto realize sufficient shielding performance of backlight without theblack matrix.

By the way, according to the sRGB (standard RGB) or EBU (EuropeanBroadcasting Union) standard, required color reproductivity for thedisplay monitors for personal computers and the LCD devices for TV is72% of the NTSC (National Television System Committee) standard orhigher. Therefore, in the case of the combination of a color filterusing photosensitive color resists formed by the popular pigmentdispersion method and a backlight unit using cold-cathode fluorescentlamps (CCFLs), each of the red, green, and blue color layers has athickness of 1.8 to 2.0 μm. For this reason, if the whole black matrixis replaced with the three-layered light-shielding sections formed byoverlapping the red, green, and blue color layers, the level differencewill be 3.6 to 4.0 μm at the maximum in the vicinities of the framearea. Here, the level difference means the difference between thethickness of the pixels (which are formed by one of the red, green, andblue color layers) and the thickness of the light-shielding sections(which are formed by three of the red, green, and blue color layers).

In recent years, there is the growing need to speed the responsecharacteristic of the LCD device up. To answer this need, it isnecessary for the cell gap (i.e., the thickness of the liquid-crystallayer) of the LCD panel to be equal to 4.0 μm or lower, preferably, atapproximately 3.0 μm. If the cell gap is decreased to such a value, thethickness difference (3.6 to 4.0 μm at the maximum), i.e., the leveldifference between the pixels and the light-shielding sections, will begreater than the cell gap (3.0 μm or less). Thus, with the color filtersfor the display monitors for personal computers and the LCD devices forTV that necessitates high-speed response characteristics, thelight-shielding sections are unable to be formed by the layeredstructure of the three color layers. This means that the light-shieldingsections need to be formed by the layered structure of the two colorlayers.

FIGS. 1A, 1B and 1C show an example of the prior-art color filters usedfor the LCD devices of this type, where the light-shielding sections areformed by two different color layers overlapped. FIG. 1A is anexplanatory partial plan view showing the pattern of the red color layerused in this color filter, FIG. 1B is an explanatory partial plan viewshowing the pattern of the blue color layer thereof, and FIG. 1C is anexplanatory partial plan view showing the pattern of the green colorlayer thereof. FIG. 2 is an explanatory partial plan view of theprior-art color filter constituted by the red, blue and green colorlayers shown in FIGS. 1A, 1B, and 1C.

The red color layer 101 used for this prior-art color filter is formedon a surface (X-Y plane) of a transparent glass plate (not shown). Thelayer 101 comprises stripe-shaped red pixel formation sections 101R andconnection sections 101L, as shown in FIG. 1A.

The stripe-shaped red pixel formation sections 101R are extended alongthe Y direction (vertical direction in FIG. 1A) and arranged along the Xdirection (horizontal direction in FIG. 1A) at predetermined intervals.The sections 101R are used for forming rectangular red pixels arrangedin the Y direction at predetermined intervals. Thus, it may be said thateach of the sections 101R is formed by red pixels and red inter-pixelparts that interconnect the adjoining red pixels.

The connection sections 101L interconnect the adjoining red pixelformation sections 101R. Moreover, the connection sections 101L definerectangular blue pixel windows 101B arranged along the Y direction atpredetermined intervals and rectangular green pixel windows 101Garranged along the Y direction at predetermined intervals. Each of theblue pixel windows 101B is located at a position where a blue pixel isto be formed. Each of the green pixel windows 101G is located at aposition where a green pixel is to be formed.

Accordingly, the red pixels are aligned along the Y direction atpredetermined intervals. The green pixels are aligned along the Ydirection at the same intervals as the red pixels in such a way as to beadjacent to the red pixels. The blue pixels are aligned along the Ydirection at the same intervals as the red pixels in such a way as to beadjacent to the green pixels. This layout or arrangement of the red,green and blue pixels thus aligned is repeatedly aligned along the Xdirection.

The blue color layer 102 used for the prior-art color filter of FIGS. 1Ato 1C is formed on the surface of the glass plate to be overlapped withthe red color layer 101. The layer 102 comprises stripe-shaped bluepixel formation sections 102B and connection sections 102L, as shown inFIG. 1B.

The stripe-shaped blue pixel formation sections 102B are extended alongthe Y direction and arranged along the X direction at predeterminedintervals. The sections 102B, which are located on such positions as tobe superposed on the corresponding blue pixel windows 101B of the redcolor layer 101, are used for forming rectangular blue pixels arrangedin the Y direction at predetermined intervals. Thus, it may be said thateach of the sections 102B is formed by blue pixels and blue inter-pixelparts that interconnect the adjoining blue pixels.

The connection sections 102L interconnect the adjoining blue pixelformation sections 102B. Moreover, the connection sections 102L definerectangular red pixel windows 102R arranged along the Y direction atpredetermined intervals and rectangular green pixel windows 102Garranged along the Y direction at predetermined intervals. Each of thered pixel windows 102R is located at a position where a red pixel is tobe formed. Each of the green pixel windows 102G is located at a positionwhere a green pixel is to be formed.

Accordingly, the red pixel windows 102R are located at such positions asto be superposed on the corresponding red pixel formation sections 101Rof the red color layer 101. The green pixel windows 102G are located atsuch positions as to be superposed on the corresponding green pixelwindows 101G of the red color layer 101.

The green color layer 103 used for the prior-art color filter of FIGS.1A to 1C is formed on the surface of the glass plate to be overlappedwith the red and blue color layers 101 and 102. The layer 103 comprisesstripe-shaped green pixel formation sections 103G, as shown in FIG. 1C.Unlike the red and blue color layers 101 and 102, the green color layer103 does not have connection sections like the connection sections 101Land 102L.

The stripe-shaped green pixel formation sections 103G are extended alongthe Y direction and arranged along the X direction at predeterminedintervals. The sections 103G, which are located on such positions as tobe superposed on the corresponding green pixel windows 101G of the redcolor layer 101 and the corresponding green pixel windows 102G of theblue color layer 102, are used for forming rectangular green pixelsarranged in the Y direction at predetermined intervals. Thus, it may besaid that each of the sections 103G is made of green pixels and greeninter-pixel parts that interconnect the adjoining green pixels.

The above-described prior-art color filter of FIGS. 1A to 1C, which isfabricated by overlapping the red, blue, and green color layers 101,102, and 103 with the above-described patterns in this order, has thestructure as shown in FIG. 2.

As seen from FIG. 2, the stripe-shaped red pixel formation sections 101Rof the red color layer 101 are overlapped with the corresponding redpixel windows 102R of the blue color layer 102, thereby defining the redpixels. This means that the exposed parts of the red pixel formationsections 101R from the corresponding red pixel windows 102R form the redpixels.

Similarly, the stripe-shaped blue pixel formation sections 102B of theblue color layer 102 are overlapped with the corresponding blue pixelwindows 102B of the red color layer 101, thereby defining the bluepixels. This means that the parts of the blue pixel formation sections102B located inside the corresponding blue pixel windows 102B form theblue pixels.

The stripe-shaped green pixel formation sections 103G of the green colorlayer 103 are overlapped with the corresponding green pixel windows 101Gof the red color layer 101 and the corresponding green pixel windows102G of the blue color layer 102, thereby defining the green pixels.This means that the parts of the green pixel formation sections 103Glocated inside the overlapped, corresponding green pixel windows 101Gand 102G form the blue pixels.

The red inter-pixel parts of the stripe-shaped red pixel formationsections 101R of the red color layer 101 are overlapped with thecorresponding connection sections 102L of the blue layer 102 or thecorresponding blue inter-pixel parts of the stripe-shaped blue pixelformation sections 102B thereof, thereby forming two-layer-structuredlight-shielding sections. These light-shielding sections, which have thetwo-layer structure formed by overlapping the red and blue color layers101 and 102, have the same pattern as the black matrix. However, thegreen inter-pixel parts of the green color layer 103 are overlapped withboth the corresponding connection sections 101L of the red color layer101 and the corresponding connection sections 102L of the blue colorlayer 102. Therefore, the light-shielding sections located at thesepositions have the three-layer structure of the red, blue and greencolor layers 101, 102 and 103.

The cross-sectional structure along the IIIA-IIIA line of FIG. 2 (i.e.,the cross-sectional structure of the part including the green pixelformation section 103G) is shown in FIG. 3A. As shown in FIG. 3A, thered, blue and green color layers 101, 102 and 103 are overlapped in thisorder on the surface of the glass plate 109. An overcoat layer 123 isformed on the green color layer 103. At the positions located over thethree-layered light-shielding sections 133 (which are disposed rightover the corresponding green inter-pixel parts of the green color layer103), photo spacers 120 are formed on the overcoat layer 123. Thesephoto spacers 120 are formed by patterning a known photoresist(photosensitive resin) film.

As clearly seen from FIG. 3A, the light-shielding section 133 has thethree-layer structure formed by overlapping the red, blue, and greencolor layers 101, 102 and 103. The photo spacers 120 are formed on theovercoat layer 123 that covers the color layers 101, 102 and 103. Thus,there is a level difference “h” between the green pixel formed by thegreen color layer 103 (i.e., the green pixel formation section 103G) andthe adjoining light-shielding section 133 thereto, where the leveldifference “h” is approximately equal to the sum of the thicknesses ofthe red and blue color layers 101 and 102.

The widths of the blue inter-pixel parts of the blue color layer 102 andthe connection sections 102L thereof are slightly larger than the widthsof the red inter-pixel parts of the red color layer 101 and theconnection sections 101L thereof. Therefore, as shown in FIG. 3A, theboth edges of the blue inter-pixel parts of the blue color layer 102 andthe connection sections 102L thereof, which are placed on the redinter-pixel parts of the red color layer 101 or the connection sections101L thereof, are contacted with the surface of the glass plate 109.

The state where a TFT substrate 126 is coupled with the color filterwith the structure of FIG. 3A is shown in FIG. 3B. In this state, asclearly seen from FIG. 3A, the cell gap “c” is equal to the sum of thelevel difference “h” and the height of the photo spacers 120.

FIG. 4A shows the state where the positions of the photo spacers 120 arechanged to those located over the blue color layer 102 in theabove-described prior-art color filter of FIG. 2. The cross-sectionalstructure along the VA-VA line in FIG. 4A (i.e., the cross-sectionalstructure of the part including the blue pixel formation section 102B ofthe layer 102) is shown in FIG. 5A.

At the positions shown in FIG. 5A, the light-shielding sections 133ahave the two-layer structure comprising the red and blue color layers101 and 102. Thus, the level difference “i” between the blue pixels andthe light-shielding sections 133a adjoining thereto is approximatelyequal to the thickness of the red color layer 101. The level difference“i” is smaller than the level difference “h” (see FIGS. 3A and 3B)between the green pixels and the light-shielding sections 133 adjoiningthereto by the thickness of the green color layer 103.

The state where the TFT substrate 126 is coupled with the color filterof FIG. 4A is shown in FIG. 5B. In this state, as clearly seen from FIG.5B, the cell gap “c” is equal to the sum of the level difference “i” andthe height of the photo spacers 120. However, the level difference “i”is smaller than the level difference “h”. Therefore, the height of thephoto spacers 120 can be increased by the gap between the differences“h” and “i”.

The cross-sectional structure along the VIA-VIA line of FIG. 4A (i.e.,the cross-sectional structure of the part including the green pixelformation section 103G) is shown in FIG. 6A. This structure is the sameas that of FIG. 3A except that the photo spacers 120 do not exist.Therefore, the level difference “j” of FIG. 6A is the same as much asthe level difference “h” of FIG. 3A. The state where the TFT substrate126 is coupled with the structure of FIG. 6A is shown in FIG. 6B. Inthis case, if the cell gap “c” is set to be equal to that of FIG. 5B,the gap “e” over the light-shielding sections 133 is equal to thesubtraction result of the level difference “j” from the cell gap “c”.Accordingly, the gap “e” is considerably smaller than the gap over thelight-shielding sections 133a (which is equal to the height of the photospacers 120).

In this way, when the photo spacers 120 are placed on the green pixelformation sections 103G (see FIG. 2), the level difference “h” will belarge. Thus, to obtain a desired value of the cell gap “c”, the heightof the photo spacers 120 needs to be decreased. Since the gap “e” overthe light-shielding sections 133 is equal to the height of the photospacers 120, the gap “e” is decreased by the decreased height of thephoto spacers 120. On the other hand, when the photo spacers 120 areplaced on the blue pixel formation sections 102B (see FIG. 4A), thelevel difference “i” between the blue pixels and the light-shieldingsections 133a is smaller than the level difference “h” between the greenpixels and the light-shielding sections 133 (i.e., i<h). Accordingly,the gap “e” over the light-shielding sections 133 can be increased byincreasing the height of the photo spacers 120.

In addition, the photo spacers 120 may be formed at the positions overthe red pixel formation sections 101R, as shown in FIG. 4B. In thiscase, the cross-sectional structure is the same as that of the casewhere the photo spacers 120 are located over the blue pixel formationsections 120B (see FIG. 5A). Therefore, the explanation about it isomitted here.

As the TFT substrate 126, for example, a TFT substrate of the IPS(In-Plane Switching) type having the structure of FIG. 7 may be used.This structure is approximately the same as that illustrated in FIG. 6of the Japanese Non-Examined Patent Publication No. 2005-241923. FIG. 7shows the structure in one of the pixel regions.

As shown in FIG. 7, the TFT substrate 126 comprises a common electrodeline 143 made of metal, a contact hole 145 for a common electrode, atransparent common electrode 146, a transparent pixel electrode 147, acontact hole 148 for the pixel electrode 147, a scanning line 149, adata line 150, a TFT 151, a source electrode 152 of the TFT 151, a drainelectrode 153 of the TFT 151, an island-shaped amorphous silicon (a-Si)film 154 for forming an active layer of the TFT 151, and a pixelauxiliary electrode 156.

The pixel electrode 147 has three zigzag-shaped comb teeth. The commonelectrode 146 has four zigzag-shaped comb teeth. The pixel electrode 147and the common electrode 146 are arranged in such a way as to bealternately engaged with each other in the region surrounded by theadjoining scanning lines 149 and the adjoining data lines 150. The twoteeth of the common electrode 146 at its each side are overlapped withthe corresponding data lines 150, respectively. The pixel auxiliaryelectrode 156 has one comb tooth superposed on the central tooth of thepixel electrode 147.

Each of the data lines 150 is electrically connected to the drainelectrode 153 of a corresponding one of the TFTs 151. Each of thescanning lines 149 is electrically connected to the gate electrode (notshown) of a corresponding one of the TFTs 151. Each of the pixelelectrodes 147 is electrically connected to the source electrode 152 ofa corresponding one of the TFTs 151 by way of a corresponding one of thecontact holes 148. Each of the common electrodes 146 is electricallyconnected to a corresponding one of the common electrode lines 143 byway of a corresponding one of the contact holes 145.

The above-described prior-art color filter shown in FIGS. 1 to 6 has thethree problems explained below.

The first problem is that the level difference “h” (see FIGS. 3A and 3B)between the green pixels and the adjoining three-layered light-shieldingsections 133 thereto is so large that the freedom of designing the cellgap “c” may be damaged.

Specifically, the level difference “h” between the green pixels and thelight-shielding sections 133, which varies dependent on the width of thesaid sections 133, is likely to be excessively large. In the case of thethickness of the overlapped parts of the red and green color layers 101and 103 being set at 70 to 90% (these values are determined inconsideration of the thickness averaging due to flow during the coatingprocess of the resist for each color) of the thickness of the red pixelformation sections 101R and that of the green pixel formation sections103G, supposing that the red pixel formation sections 101R are 2.0 μm inthickness, the blue pixel formation sections 102B are 2.0 μm inthickness, the green pixel formation sections 103G are 2.0 μm inthickness, and the overcoat layer 123 is 1.0 μm in thickness, theoverall thickness of the light-shielding sections 133 will beapproximately 5 μm to approximately 6 μm while the overall thickness ofthe respective pixel formation sections will be 3.0 μm. (At this time,the overcoat layer 123 will be considerably thin, although it depends onthe viscosity.) This means that the level difference “h” will beapproximately 2.0 μm to approximately 3.0 μm, which is extremely large.For example, if the height difference “h” is 3.0 μm, the cell gap “c”over the green pixel is difficult to be set at 3.0 μm or less, whichmeans that that the freedom of designing the cell gap “c” is damagedvastly.

To reduce the level difference “h”, the parts of the green color layer103 (i.e., the green inter-pixel parts of the green pixel formationsections 103G) that form the three-layered light-shielding sections 133may be selectively removed by polishing. However, the green pixelformation sections 103G of the green color layer 103 are arranged on thealmost entire surfaces of the corresponding light-shielding sections133, and the total area of the green color layer 103 to be polished andremoved is very wide. Therefore, even if a polishing machine is used topolish the entire surface of the said color filter, the said parts aredifficult to be removed. Moreover, since such the polishing operationnecessitates a long time, the tact time increases extensively and themass productivity is damaged.

The second problem is that local gap defects are likely to occur due toplastic deformation or breakdown of the photo spacers 120 and that thecolor layers are difficult to be thickened to raise the colorreproductivity.

Specifically, when the cell gap “c” is constant, the height of the photospacers 120 is determined by the level difference “h” between the greenpixels and the three-layered light-shielding sections 133. The leveldifference “h” is approximately equal to the sum of the thicknesses ofthe red and blue color layers 101 and 102. Therefore, thickening the redand blue color layers 101 and 102 to raise the color reproductivityleads to the increase of the level difference “h” and the heightdecrease of the photo spacers 120. Accordingly, it is difficult to raisethe color reproductivity by thickening the red and blue color layers 101and 102 (and the green color layer 103).

Moreover, the amount of possible elastic deformation of the photospacers 120 decreases as their height decreases. Thus, the more theheight of the spacers 120 is reduced due to the increase of thedifference “h”, the less the deformation margin of the spacers 120against the local pressure stress applied to the display surface fromthe outside of the LCD panel. As a result, local gap defects are likelyto occur due to plastic deformation or breakdown of the photo spacers120.

The third problem is that the two-layered light-shielding sections 133ain the effective display region do not utilize effectively the operationcharacteristics in the normally black mode of the IPS or VA (VerticallyAligned) type LCD device and the light-shielding effect for thebacklight with the metal lines on the TFT substrate 126.

Specifically, with the above-described prior-art color filter of FIGS.1A to 6B, the two-layered light-shielding sections 133a comprising thered and blue color layers 101 and 102 (where the OD value is maximized)are placed in not only the region where a high OD value is necessary butalso the region where an OD value may be low. Therefore, thethree-layered light-shielding sections 133 comprising the red, blue andgreen color layers 101, 102 and 103 are formed at the positions adjacentto the green pixels. As a result, the cell gap “c” has to be determinedin conformity with the large level difference “h” between the greenpixels and the light-shielding sections 133. For this reason, the gap“e” (see FIG. 6B) between the three-layered light-shielding sections 133and the TFT substrate 126 may be very narrow if the cell gap “c” is setat particular values. This means that a problem that foreign objects arelikely to be caught in the narrowed gap “e” occurs. This is because ifforeign objects are caught in the narrowed gap “e”, gap defect will begenerated in the light-shielding sections 133, which gives bad effectsto the display quality.

SUMMARY OF THE INVENTION

The present invention was created in consideration of theabove-described first to third problems in the prior-art color filtershown in FIGS. 1A to 6B.

An object of the present invention is to provide a color filter thatreduces the level difference between the two-layered light-shieldingsections comprising two different color layers and the colored materialsthat form the pixels of the respective colors by an easy method, amethod of fabricating the color filter, and a LCD device using the colorfilter.

Another object of the present invention is to provide a color filterthat can remove easily the parts existing on the two-layeredlight-shielding sections comprising two different color layers bypolishing, where the parts are formed by the other color layer, a methodof fabricating the color filter, and a LCD device using the colorfilter.

Still another object of the present invention is to provide a colorfilter whose respective color layers can be patterned easily to obtain adesired light-shielding performance using the two-layeredlight-shielding sections comprising two different color layers, a methodof fabricating the color filter, and a LCD device using the colorfilter.

A further object of the present invention is to provide a LCD devicethat has high contrast, good color reproductivity and high-speedresponse characteristics without a black matrix.

The above objects together with others not specifically mentioned willbecome clear to those skilled in the art from the following description.

According to a first aspect of the present invention, a color filter isprovided, which comprises:

a transparent support;

a first color layer formed on the support;

the first color layer having stripe-shaped first pixel formationsections, second color pixel windows, and third color pixel windows,which are arranged at predetermined intervals, respectively;

a second color layer formed to overlap with the first color layer;

the second color layer having stripe-shaped second color pixel formationsections, first color pixel windows, and third color pixel windows,which are arranged at predetermined intervals, respectively; and

a third color layer having island-shaped third color pixel formationsections apart from each other;

wherein the first color pixel formation sections of the first colorlayer are overlapped with the first color pixel windows of the secondcolor layer, thereby defining first color pixels; and the second colorpixel formation sections of the second color layer are overlapped withthe second color pixel windows of the first color layer, therebydefining second color pixels;

wherein the third color pixel formation sections of the third colorlayer are arranged in the third color pixel windows of the first colorlayer and the third color pixel windows of the second color layer, thethird color pixel windows of the first color layer being overlapped withthe third color pixel windows of the second color layer, therebydefining third color pixels; and

wherein overlapped parts of the first color layer and the second colorlayer function as light-shielding sections.

With the color filter according to the first aspect of the presentinvention, the first color layer and the second color layer each havingthe above-described structure are formed on the support. The overlappedparts of the first color layer and the second color layer function asthe light-shielding sections. Therefore, a black matrix for forming thelight-shielding sections is unnecessary.

The third color pixel formation sections of the third color layer areisland-shaped and arranged in the third color pixel windows of the firstcolor layer and the third color pixel windows of the second color layeroverlapped with each other. Therefore, by appropriately adjusting thesize of the third color pixel formation sections, the third color pixelformation sections can be scarcely placed on the overlapped parts of thefirst and second color layers having the function of the light-shieldingsections. This means that the level difference between thelight-shielding sections and the first, second or third color layer(i.e., the colored materials that form the pixels of the respectivecolors) can be reduced. In addition, such the reduction of the leveldifference can be realized by an easy method. This is because thereduction of the level difference between the light-shielding sectionsand the first, second or third color layer can be obtained by making thethird color pixel formation sections of the third color layerisland-shaped to be apart from each other.

Moreover, the third color pixel formation sections can be arranged onthe support in such a way that the peripheries of the third color pixelformation sections are scarcely placed on the overlapped parts of thefirst and second color layers that provide the light-shielding function.Therefore, the amount of the third color layer (i.e., the third colorpixel formation sections) placed on the light-shielding sections islimited to a small value. As a result, the third color pixel formationsections placed on the light-shielding sections can be easily removed bypolishing.

Furthermore, it is sufficient for the invention that the first colorlayer is formed to have the stripe-shaped first color pixel formationsections, the second color windows, and the third color windows, thatthe second color layer is formed to have the stripe-shaped second colorpixel formation sections, the first color windows, and the third colorwindows, and that the third color layer is formed to have theisland-shaped pixel formation sections. Therefore, the patterningprocess of the respective color layers (i.e., the first, second, andthird color layers) to obtain a desired light-shielding performance canbe conducted easily.

In a preferred embodiment of the color filter according to the firstaspect of the present invention, the first color pixel formationsections of the first color layer are arranged along a first directionat predetermined intervals and are extended along a second directionperpendicular to the first direction, and the second and third colorpixel windows of the first color layer are defined by connectionsections that connect the first color pixel formation sections adjacentto each other. Moreover, the second color pixel formation sections ofthe second color layer are arranged along the first direction atpredetermined intervals and are extended along the second direction, andthe first and third color pixel windows of the second color layer aredefined by connection sections that connect the second color pixelformation sections adjacent to each other.

In another preferred embodiment of the color filter according to thefirst aspect of the present invention, peripheries of the third colorpixel formation sections are overlapped with the light-shieldingsections to have overlapped widths of 5.0 μm or less (preferably, 3.0 μmor less). In this embodiment, the peripheries of the third color pixelformation sections are placed on the light-shielding sections; however,the effect of the overlapped peripheries is small and thus, it can besuppressed to the extent that no problem arises. Accordingly, there isan additional advantage that the process step of removing the overlappedperipheries of the third color pixel formation sections is unnecessary.

In the embodiment where the peripheries of the third color pixelformation sections are overlapped with the light-shielding sections, itis preferred that spacers are additionally arranged to bury or fill theoverlapped peripheries of the third color pixel formation sections withthe light-shielding sections. This is because, if so, the effect of theoverlapped peripheries can be reduced.

In a further preferred embodiment of the color filter according to thefirst aspect of the present invention, the peripheries of the thirdcolor pixel formation sections are not overlapped with thelight-shielding sections. In this embodiment, since the third colorpixel formation sections do not exist on the light-shielding sections,the light-shielding sections have a two-layered structure completely.Thus, there is an additional advantage that the level difference betweenthe light-shielding sections and the first, second or third color pixelscan be reduced furthermore.

In the embodiment of the color filter where the peripheries of the thirdcolor pixel formation sections are not overlapped with thelight-shielding sections, it is preferred to have spacers arranged onthe light-shielding sections. In this embodiment, there is an additionaladvantage that the spacers can be placed at any positions on thelight-shielding sections, because the third color pixel formationsections are not placed on the light-shielding sections.

In a still further preferred embodiment of the color filter according tothe first aspect of the present invention, the first color layer is oneof a red color layer and a blue color layer, and the second color layeris the other. In this embodiment, there is an additional advantage thatthe light-shielding rate is maximized among the two-layered structurescomprising two of a red color layer, a blue color layer, and a greencolor layer.

In a still further preferred embodiment of the color filter according tothe first aspect of the present invention, the first color layer or thesecond color layer is a red color layer. In this embodiment, there is anadditional advantage that the light with a wavelength that affectssignificantly the current leakage of the TFTs can be shieldedeffectively.

According to a second aspect of the present invention, a method offabricating the color filter according to the first aspect of theinvention is provided. This method comprises the steps of:

forming a first color layer on a transparent support; the first colorlayer having stripe-shaped first color pixel formation sections, secondcolor pixel windows, and third color pixel windows, which are arrangedat predetermined intervals, respectively;

forming a second color layer to overlap with the first color layer; thesecond color layer having stripe-shaped second color pixel formationsections, first color pixel windows, and third color pixel windows,which are arranged at predetermined intervals, respectively; and

forming a third color layer having island-shaped third color pixelformation sections apart from each other;

wherein in the step of forming the second color layer, the first colorpixel formation sections of the first color layer are overlapped withthe first color pixel windows of the second color layer, therebydefining first color pixels; and the second color pixel formationsections of the second color layer are overlapped with the second colorpixel windows of the first color layer, thereby defining second colorpixels;

wherein in the step of forming the third color layer, the third colorpixel formation sections of the third color layer are arranged in thethird color pixel windows of the first color layer and the third colorpixel windows of the second color layer, the third color pixel windowsof the first color layer being overlapped with the third color pixelwindows of the second color layer, thereby defining third color pixels;and

wherein overlapped parts of the first color layer and the second colorlayer function as light-shielding sections.

With the method of fabricating the color filter according to the secondaspect of the present invention, as explained above, the first colorlayer, the second color layer, and the third color layer, each havingthe above-described structure, are formed on the support successively,thereby forming the overlapped parts of the first color layer and thesecond color layer that function as the light-shielding sections.Therefore, a black matrix for forming the light-shielding sections isunnecessary.

The third color pixel formation sections of the third color layer areisland-shaped and arranged in the third color pixel windows of the firstcolor layer and the third color pixel windows of the second color layeroverlapped with each other. Therefore, by appropriately adjusting thesize of the third color pixel formation sections, the third color pixelformation sections can be scarcely placed on the overlapped parts of thefirst and second color layers having the function of the light-shieldingsections. This means that the level difference between thelight-shielding sections and the first, second or third color layer(i.e., the colored materials that form the pixels of the respectivecolors) can be reduced. In addition, such the reduction of the leveldifference can be realized by an easy method. This is because thereduction of the level difference between the light-shielding sectionsand the first, second or third color layer can be obtained by making thethird color pixel formation sections of the third color layerisland-shaped to be apart from each other.

Moreover, the third color pixel formation sections can be arranged onthe support in such a way that the peripheries of the third color pixelformation sections are scarcely placed on the overlapped parts of thefirst and second color layers that provide the light-shielding function.Therefore, the amount of the third color layer (i.e., the third colorpixel formation sections) placed on the light-shielding sections islimited to a small value. As a result, the third color pixel formationsections placed on the light-shielding sections can be easily removed bypolishing.

Furthermore, it is sufficient for the invention that the first colorlayer is formed to have the stripe-shaped first color pixel formationsections, the second color windows, and the third color windows, thatthe second color layer is formed to have the stripe-shaped second colorpixel formation sections, the first color windows, and the third colorwindows, and that the third color layer is formed to have theisland-shaped pixel formation sections. Therefore, the patterningprocess of the respective color layers (i.e., the first, second, andthird color layers) to obtain a desired light-shielding performance canbe conducted easily.

In a preferred embodiment of the method according to the second aspectof the present invention, in the step of forming the first color layer,the first color pixel formation sections of the first color layer arearranged along a first direction at predetermined intervals and areextended along a second direction perpendicular to the first direction;

the second color pixel windows and the third color pixel windows of thefirst color layer are defined by connection sections that connect thefirst color pixel formation sections thereof adjacent to each other;

and wherein in the step of forming the second color layer, the secondcolor pixel formation sections of the second color layer are arrangedalong the first direction at predetermined intervals and are extendedalong the second direction; and

the first color pixel windows and the third color pixel windows of thesecond color layer are defined by connection sections that connect thesecond color pixel formation sections thereof adjacent to each other.

In another preferred embodiment of the method according to the secondaspect of the present invention, in the step of forming the third colorlayer, peripheries of the third color pixel formation sections areoverlapped with the light-shielding sections to have overlapped widthsof 5.0 μm or less (preferably, 3.0 μm or less). In this embodiment, theperipheries of the third color pixel formation sections are placed onthe light-shielding sections; however, the effect of the overlappedperipheries is small and thus, it can be suppressed to the extent thatno problem arises. Accordingly, there is an additional advantage thatthe process step of removing the overlapped peripheries of the thirdcolor pixel formation sections is unnecessary.

In the embodiment where peripheries of the third color pixel formationsections are overlapped with the light-shielding sections in the step offorming the third color layer, it is preferred that a step of formingspacers in such a way as to bury or fill the overlapped peripheries ofthe third color pixel formation sections with the light-shieldingsections is additionally performed. This is because, if so, the effectof the overlapped peripheries can be reduced.

In a further preferred embodiment of the method according to the secondaspect of the present invention, after the step of forming the thirdcolor layer is completed, a step of polishing the third color layer iscarried out to remove peripheries of the third color pixel formationsections placed on the light-shielding sections. In this embodiment,(the peripheries of) the third color pixel formation sections existingon the light-shielding sections can be surely removed. Thus, there is anadditional advantage that the level difference between thelight-shielding sections and the first, second or third color pixels canbe reduced furthermore.

In a still another preferred embodiment of the method according to thesecond aspect of the present invention, the first color layer is one ofa red color layer and a blue color layer, and the second color layer isthe other. In this embodiment, there is an additional advantage that thelight-shielding rate is maximized among the two-layered structurescomprising two of a red color layer, a blue color layer, and a greencolor.

In a still further preferred embodiment of the method according to thesecond aspect of the present invention, the first color layer or thesecond color layer is a red color layer. In this embodiment, there is anadditional advantage that the light with a wavelength that affectssignificantly the current leakage of the TFTs can be shieldedeffectively.

According to a third aspect of the present invention, another colorfilter is provided, which comprises:

a transparent support;

a first color layer formed on the support;

the first color layer having stripe-shaped first color pixel formationsections and second-and-third color pixel windows, which are arranged atpredetermined intervals along a first direction, respectively;

a second color layer formed to overlap with the first color layer;

the second color layer having stripe-shaped second color pixel formationsections and first-and-third color pixel windows, which are arranged atpredetermined intervals along the first direction, respectively; and

a third color layer having island-shaped third color pixel formationsections apart from each other;

wherein the second color pixel formation sections of the second colorlayer are overlapped with second color pixel subwindows of thesecond-and-third color pixel windows of the first color layer; and thefirst-and-third color pixel windows of the second color layer arerespectively overlapped with the first color pixel formation sections ofthe first color layer and third color pixel subwindows of thesecond-and-third color pixel windows thereof;

wherein the third color pixel formation sections of the third colorlayer are respectively arranged in the third color pixel subwindows ofthe second-and-third color pixel windows of the first color layer andthe third color pixel subwindows of the first-and-third color pixelwindows of the second color layer, the third color pixel subwindows ofthe second-and-third color pixel windows of the first color layer beingoverlapped with the third color pixel subwindows of the first-and-thirdcolor pixel windows of the second color layer;

wherein the first color pixel formation sections of the first colorlayer, which are overlapped with the first-and-third color pixel windowsof the second color layer and the third color pixel formation sectionsof the third color layer, define first color pixels;

the second color pixel formation sections of the second color layer,which are overlapped with the second-and-third color pixel windows ofthe first color layer and the third color pixel formation sections ofthe third color layer, define second color pixels;

the third color pixel formation sections of the third color layer, whichare overlapped with the second-and-third color pixel windows of thefirst color layer and the first-and-third color pixel windows of thesecond color layer, define third color pixels; and

wherein first light-shielding sections extending along the firstdirection are formed by overlapped parts of the first color layer andthe second color layer; and

second light-shielding sections extending along a second directionperpendicular to the first direction are formed by overlapped parts ofthe first color layer and the second color layer, overlapped parts ofthe second color layer and the third color layer, and overlapped partsof the third color layer and the first color layer.

Here, it may be said that each of the second-and-third color pixelwindows of the first color layer comprises the second color pixelsubwindow covered with the second color layer and the third color pixelsubwindow not covered with the second color layer. Similarly, it may besaid that each of the first-and-third color pixel windows of the secondcolor layer comprises the third color pixel subwindow covered with thethird color layer and the first color pixel subwindow not covered withthe third color layer.

With the color filter according to the third aspect of the presentinvention, the first color layer and the second color layer each havingthe above-described structure are formed on the support. The firstlight-shielding sections extending along the first direction are formedby the overlapped parts of the first color layer and the second colorlayer. The second light-shielding sections extending along the seconddirection are formed by the overlapped parts of the first and secondcolor layers, the overlapped parts of the second and third color layers,and the overlapped parts of the third and first color layers (i.e., thetwo color layers adjoining to each other). Therefore, a black matrix forforming the light-shielding sections is unnecessary.

The third color pixel formation sections of the third color layer, whichdefine the third color pixels by the overlapping with thesecond-and-third color pixel windows of the first color layer and thefirst-and-third color pixel windows of the second color layer, areisland-shaped apart from each other. Therefore, by appropriatelyadjusting the size of the third color pixel formation sections, thethird color pixel formation sections can be scarcely placed on theoverlapped parts of the first and second color layers having thefunction of the first light-shielding sections extending along the firstdirection. This means that the level difference between the firstlight-shielding sections and the first, second or third color layer(i.e., the colored materials that form the pixels of the respectivecolors) can be reduced. In addition, such the reduction of the leveldifference can be realized by an easy method. This is because thereduction of the level difference between the first light-shieldingsections and the first, second or third color layer can be obtained bymaking the third color pixel formation sections of the third color layerisland-shaped to be apart from each other.

Moreover, by appropriately adjusting the size of the third color pixelformation sections of the third color layer, the third color pixelformation sections can be arranged on the support in such a way that theperipheries of the third color pixel formation sections are scarcelyplaced on the overlapped parts of the first and second color layers thatprovide the first light-shielding function. Therefore, the amount of thethird color layer (i.e., the third color pixel formation sections)placed on the first light-shielding sections is limited to a smallvalue. As a result, the third color pixel formation sections placed onthe first light-shielding sections can be easily removed by polishing.

Furthermore, it is sufficient for the invention that the first colorlayer is formed to have the stripe-shaped first color pixel formationsections and the second-and-third color pixel windows, that the secondcolor layer is formed to have the stripe-shaped second color pixelformation sections and the first-and-third color pixel windows, and thatthe third color layer is formed to have the island-shaped pixelformation sections. Therefore, the patterning process of the respectivecolor layers (i.e., the first, second, and third color layers) to obtaina desired light-shielding performance can be conducted easily.

In a preferred embodiment of the color filter according to the thirdaspect of the present invention, the second-and-third color pixelwindows of the first color layer are defined by connection sections thatconnect the first color pixel formation sections adjoining to eachother, and the first-and-third color pixel windows of the second colorlayer are defined by connection sections that connect the second colorpixel formation sections adjoining to each other.

In another preferred embodiment of the color filter according to thethird aspect of the present invention, peripheries of the third colorpixel formation sections are overlapped with the first light-shieldingsections to have overlapped widths of 5.0 μm or less (preferably, 3.0 μmor less). In this embodiment, the peripheries of the third color pixelformation sections are placed on the first light-shielding sections;however, the effect of the overlapped peripheries is small and thus, itcan be suppressed to the extent that no problem arises. Accordingly,there is an additional advantage that the process step of removing theoverlapped peripheries of the third color pixel formation sections isunnecessary.

In the embodiment where the peripheries of the third color pixelformation sections are overlapped with the first light-shieldingsections, it is preferred that spacers are additionally arranged to buryor fill the overlapped peripheries of the third color pixel formationsections with the first light-shielding sections. This is because, ifso, the effect of the overlapped peripheries can be reduced.

In a further preferred embodiment of the color filter according to thethird aspect of the present invention, peripheries of the third colorpixel formation sections are not overlapped with first thelight-shielding sections. In this embodiment, since the third colorpixel formation sections do not exist on the first light-shieldingsections, the first light-shielding sections have a two-layeredstructure completely. Thus, there is an additional advantage that thelevel difference between the first light-shielding sections and thefirst, second or third color pixels can be reduced furthermore.

In the embodiment of the color filter where the peripheries of the thirdcolor pixel formation sections are not overlapped with the firstlight-shielding sections, it is preferred to have spacers arranged onthe first light-shielding sections. In this embodiment, there is anadditional advantage that the spacers can be placed at any positions onthe first light-shielding sections, because the third color pixelformation sections are not placed on the first light-shielding sections.

In a still further preferred embodiment of the color filter according tothe third aspect of the present invention, the first color layer is oneof a red color layer and a blue color layer, and the second color layeris the other. In this embodiment, there is an additional advantage thatthe light-shielding rate is maximized among the two-layered structurescomprising two of a red color layer, a blue color layer, and a greencolor.

In a still further preferred embodiment of the color filter according tothe third aspect of the present invention, the first color layer or thesecond color layer is a red color layer. In this embodiment, there is anadditional advantage that the light with a wavelength that affectssignificantly the current leakage of the TFTs can be shieldedeffectively.

According to a fourth aspect of the present invention, a method offabricating the color filter according to the third aspect of theinvention is provided. This method comprises the steps of:

forming a first color layer on a transparent support; the first colorlayer having stripe-shaped first color pixel formation sections andsecond-and-third color pixel windows, which are arranged atpredetermined intervals along a first direction, respectively;

forming a second color layer to overlap with the first color layer; thesecond color layer having stripe-shaped second color pixel formationsections and first-and-third color pixel windows, which are arranged atpredetermined intervals along the first direction, respectively; and

forming a third color layer having island-shaped third color pixelformation sections apart from each other;

wherein in the step of forming the second color layer, the second colorpixel formation sections of the second color layer are overlapped withsecond color pixel subwindows of the second-and-third color pixelwindows of the first color layer; and the first-and-third color pixelwindows of the second color layer are respectively overlapped with thefirst color pixel formation sections of the first color layer and thirdcolor pixel subwindows of the second-and-third color pixel windowsthereof;

wherein in the step of forming the third color layer, the third colorpixel formation sections of the third color layer are arranged in thethird color pixel subwindows of the second-and-third color pixel windowsof the first color layer and the third color pixel subwindows of thefirst-and-third color pixel windows of the second color layer, the thirdcolor pixel subwindows of the second-and-third color pixel windows beingoverlapped with the third color pixel subwindows of the first-and-thirdcolor pixel windows being overlapped;

wherein the first color pixel formation sections of the first colorlayer, which are overlapped with the first-and-third color pixel windowsof the second color layer and the third color pixel formation sectionsof the third color layer, define first color pixels;

the second color pixel formation sections of the second color layer,which are overlapped with the second-and-third color pixel windows ofthe first color layer and the third color pixel formation sections ofthe third color layer, define second color pixels;

the third color pixel formation sections of the third color layer, whichare overlapped with the second-and-third color pixel windows of thefirst color layer and the first-and-third color pixel windows of thesecond color layer, define third color pixels; and

wherein first light-shielding sections extending along the firstdirection are formed by overlapped parts of the first color layer andthe second color layer; and

second light-shielding sections extending along a second directionperpendicular to the first direction are formed by overlapped parts ofthe first color layer and the second color layer, overlapped parts ofthe second color layer and the third color layer, and overlapped partsof the third color layer and the first color layer.

With the method of fabricating a color filter according to the fourthaspect of the present invention, as explained above, the first colorlayer, the second color layer, and the third color layer, each havingthe above-described structure, are formed on the support successively.Thus, the first light-shielding sections extending along the firstdirection are formed by the overlapped parts of the first color layerand the second color layer. At the same time, the second light-shieldingsections extending along the second direction are formed by theoverlapped parts of the first color layer and the second color layer,the overlapped parts of the second color layer and the third colorlayer, and the overlapped parts of the third color layer and the firstcolor layer. Therefore, a black matrix for forming the first and secondlight-shielding sections is unnecessary.

The third color pixel formation sections of the third color layer, whichdefine the third color pixels by overlapping them with the third colorpixel subwindows of the second-and-third color pixel windows of thefirst color layer and the third color pixel subwindows of thefirst-and-third color pixel windows of the second color layer, areisland-shaped apart from each other. Therefore, by appropriatelyadjusting the size of the third color pixel formation sections, thethird color pixel formation sections can be scarcely placed on theoverlapped parts of the first and second color layers having thefunction of the first light-shielding sections. This means that thelevel difference between the first light-shielding sections and thefirst, second or third color layer (i.e., the colored materials thatform the pixels of the respective colors) can be reduced. In addition,such the reduction of the level difference can be realized by an easymethod. This is because the reduction of the level difference betweenthe first light-shielding sections and the first, second or third colorlayer can be obtained by making the third color pixel formation sectionsof the third color layer island-shaped to be apart from each other.

Moreover, the third color pixel formation sections can be arranged onthe support in such a way that the peripheries of the third color pixelformation sections are scarcely placed on the overlapped parts of thefirst and second color layers that provide the first light-shieldingfunction. Therefore, the amount of the third color layer (i.e., thethird color pixel formation sections) placed on the firstlight-shielding sections is limited to a small value. As a result, thethird color pixel formation sections placed on the first light-shieldingsections can be easily removed by polishing.

Furthermore, it is sufficient for the invention that the first andsecond color layers are respectively formed to have the stripe-shapedpixel formation sections and the connection sections that connectingthem, and that the third color layer is formed to have the island-shapedpixel formation sections. Therefore, the patterning process of therespective color layers (i.e., the first, second, and third colorlayers) to obtain a desired light-shielding performance can be conductedeasily.

In a preferred embodiment of the method according to the fourth aspectof the present invention, the second-and-third color pixel windows ofthe first color layer are defined by connection sections that connectthe first color pixel formation sections adjoining to each other. Thefirst-and-third color pixel windows of the second color layer aredefined by connection sections that connect the second color pixelformation sections adjoining to each other.

In another preferred embodiment of the method according to the fourthaspect of the present invention, in the step of forming the third colorlayer, peripheries of the third color pixel formation sections areoverlapped with the first light-shielding sections to have overlappedwidths of 5.0 μm or less (preferably, 3.0 μm or less). In thisembodiment, the peripheries of the third color pixel formation sectionsare placed on the first light-shielding sections; however, the effect ofthe overlapped peripheries is small and thus, it can be suppressed tothe extent that no problem arises. Accordingly, there is an additionaladvantage that the process step of removing the overlapped peripheriesof the third color pixel formation sections is unnecessary.

In the embodiment where peripheries of the third color pixel formationsections are overlapped with the light-shielding sections in the step offorming the third color layer, it is preferred that a step of formingspacers in such a way as to bury or fill the overlapped peripheries ofthe third color pixel formation sections with the first light-shieldingsections is additionally performed. This is because, if so, the effectof the overlapped peripheries can be reduced.

In a further preferred embodiment of the method according to the fourthaspect of the present invention, after the step of forming the thirdcolor layer is completed, a step of polishing the third color layer iscarried out to remove peripheries of the third color pixel formationsections placed on the first light-shielding sections. In thisembodiment, since (the peripheries of) the third color pixel formationsections do not exist on the first light-shielding sections, the firstlight-shielding sections have a two-layered structure completely. Thus,there is an additional advantage that the level difference between thefirst light-shielding sections and the first, second or third colorpixels can be reduced furthermore.

In a still another preferred embodiment of the method according to thefourth aspect of the present invention, the first color layer is one ofa red color layer and a blue color layer, and the second color layer isthe other. In this embodiment, there is an additional advantage that thelight-shielding rate is maximized among the two-layered structurescomprising two of a red color layer, a blue color layer, and a greencolor.

In a still further preferred embodiment of the method according to thefourth aspect of the present invention, the first color layer or thesecond color layer is a red color layer. In this embodiment, there is anadditional advantage that the light with a wavelength that affectssignificantly the current leakage of the TFTs can be shieldedeffectively.

According to a fifth aspect of the present invention, a LCD device isprovided, which comprises:

a first substrate having the color filter according to the first orthird aspect of the invention described above; and

a second substrate having active elements for switching.

With the LCD device according to the fifth aspect of the presentinvention, since the first substrate having the above-described colorfilter according to the first or third aspect of the invention and thesecond substrate having active elements for switching are provided, highcontrast, good color reproductivity and high-speed responsecharacteristics are obtained without a black matrix.

In a preferred embodiment of the LCD device according to the fifthaspect of the present invention, the device is designed to operate in anormally black mode. A common electrode formed on the second substratecomprises shielding sections for shielding electric field leaked fromthe second substrate. The shielding sections conduct theirlight-shielding operation in vicinities of scanning lines formed on thesecond substrate.

In another preferred embodiment of the LCD device according to the fifthaspect of the present invention, the first light-shielding sections ofthe color filter are used for shielding light at corresponding locationsto scanning lines formed on the second substrate, and the secondlight-shielding sections of the color filter are used for shieldinglight at corresponding locations to data lines formed on the secondsubstrate.

In still another preferred embodiment of the LCD device according to thefifth aspect of the present invention, the second light-shieldingsections of the color filter are assigned to locations where backlightis shielded by wiring lines formed on the second substrate, and thefirst light-shielding sections of the color filter are assigned tolocations where backlight is not shielded by wiring lines formed on thesecond substrate.

In short, the color filters according to the first and third aspects ofthe invention have the following advantages (a), (b) and (c):

(a) The level difference between the two-layered light-shieldingsections comprising two different color layers and the colored materialsthat form the pixels of the respective colors can be reduced by an easymethod.

(b) The parts existing on the two-layered light-shielding sectionscomprising two different color layers, where the parts are formed by theother color layer, can be removed easily by polishing.

(c) The respective color layers can be patterned easily to obtain adesired light-shielding performance using the two-layeredlight-shielding sections comprising two different color layers.

The methods of fabricating a color filter according to the second andfourth aspects of the invention have an advantage that the color filtersaccording to the first and third aspects of the invention can be easilyfabricated, respectively.

The LCD device according to the fifth aspect of the invention has anadvantage that high contrast and good color reproductivity can beobtained without a black matrix, and that high-speed responsecharacteristics can be obtained because a narrower gap than that of theprior-art LCD devices is realized.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the present invention may be readily carried into effect,it will now be described with reference to the accompanying drawings.

FIGS. 1A to 1C show the patterns of the color layers used in a prior-artcolor filter. FIG. 1A is an explanatory partial plan view of the redcolor layer, FIG. 1B is an explanatory partial plan view of the bluecolor layer, and FIG. 1C is an explanatory partial plan view of thegreen color layer.

FIG. 2 is an explanatory partial plan view of the prior-art color filtercomprising the color layers of FIGS. 1A to 1C, which shows an example ofthe layout of the photo spacers.

FIG. 3A is an explanatory partial cross-sectional view along the lineIIIA-IIIA in FIG. 2, and FIG. 3B is an explanatory partialcross-sectional view showing the state where the TFT substrate iscoupled with the structure of FIG. 3A.

FIGS. 4A and 4B are explanatory partial plan views of the prior-artcolor filter of FIGS. 1A to 1C showing other examples of the layout ofthe photo spacers, respectively.

FIG. 5A is an explanatory partial cross-sectional view along the lineVA-VA in FIG. 4A, and FIG. 5B is an explanatory partial cross-sectionalview showing the state where the TFT substrate is coupled with thestructure of FIG. 5A.

FIG. 6A is an explanatory partial cross-sectional view along the lineVIA-VIA in FIG. 4A, and FIG. 6B is an explanatory partialcross-sectional view showing the state where the TFT substrate iscoupled with the structure of FIG. 6A.

FIG. 7 is a partial plan view showing the structure of the TFT substratecoupled with the prior-art color filter of FIG. 2.

FIGS. 8A to 8C show the patterns of the color layers of a color filteraccording to a first embodiment of the invention. FIG. 8A is anexplanatory partial plan view of the red color layer, FIG. 8B is anexplanatory partial plan view of the blue color layer, and FIG. 8C is anexplanatory partial plan view of the green color layer.

FIGS. 9A to 9C show the process steps of a method of fabricating thecolor filter according to the first embodiment of FIG. 2. FIG. 9A is anexplanatory partial plan view of the filter showing the state where thered and blue color layers of FIGS. 8A and 8B are formed on thetransparent glass plate. FIG. 9B is an explanatory partial plan view ofthe filter showing the state where the green color layer of FIG. 8C isformed on the structure of FIG. 9A. FIG. 9C is an explanatory partialplan view of the filter showing the state where the overlapped parts ofthe island-shaped green pixel formation sections with thelight-shielding sections are removed by polishing from the state of FIG.9B.

FIG. 10A is an explanatory partial cross-sectional view along the lineXA-XA in FIG. 9B, and FIG. 10B is an explanatory partial cross-sectionalview along the line XB-XB in FIG. 9C.

FIG. 11A is an explanatory partial cross-sectional view along the lineXIA-XIA in FIG. 9B, and FIG. 11B is an explanatory partialcross-sectional view along the line XIB-XIB in FIG. 9C.

FIG. 12A is an explanatory partial plan view of the color filteraccording to the first embodiment, which shows an example of the layoutof the photo spacers, and FIG. 12B is an explanatory partialcross-sectional view along the line XIIB-XIIB in FIG. 12A.

FIG. 13A is an explanatory partial plan view of the color filteraccording to the first embodiment, which shows another example of thelayout of the photo spacers, and FIG. 13B is an explanatory partialcross-sectional view along the line XIIIB-XIIIB in FIG. 13A.

FIG. 14 is an explanatory partial cross-sectional view showing the statewhere the TFT substrate is coupled with the color filter according tothe first embodiment shown in FIGS. 12A and 12B.

FIG. 15 is an explanatory partial cross-sectional view showing the statewhere the TFT substrate is coupled with the color filter according tothe first embodiment shown in FIGS. 13A and 13B.

FIG. 16 is a partial plan view showing the structure of the TFTsubstrate coupled with the color filter according to the firstembodiment of the invention.

FIG. 17 is an explanatory partial cross-sectional view of a LCD devicecomprising an opposite substrate using the color filter according to thefirst embodiment of the invention and the TFT substrate of FIG. 16coupled with the opposite substrate, which shows the cross-sectionalstructure of the device along the line XVII-XVII in FIG. 16.

FIG. 18A is an explanatory partial cross-sectional view along the lineXVIIIA-XVIIIA in FIG. 16, which shows the cross-sectional structure ofthe TFT substrate of FIG. 16, and FIG. 18B is an explanatory partialcross-sectional view along the line XVIIIB-XVIIIB in FIG. 16, whichshows the cross-sectional structure of the TFT substrate of FIG. 16.

FIGS. 19A to 19C show the patterns of the color layers of a color filteraccording to a second embodiment of the invention. FIG. 19A is anexplanatory partial plan view of the red color layer, FIG. 19B is anexplanatory partial plan view of the blue color layer, and FIG. 19C isan explanatory partial plan view of the green color layer.

FIGS. 20A to 20C show the process steps of a method of fabricating thecolor filter according to the second embodiment of FIGS. 19A to 19C.FIG. 20A is an explanatory partial plan view showing the state where thered and blue color layers of FIGS. 19A and 19B are formed on thetransparent glass plate. FIG. 20B is an explanatory partial plan viewshowing the state where the green color layer of FIG. 19C is formed onthe structure of FIG. 20A. FIG. 20C is an explanatory partial plan viewshowing the state where the overlapped parts of the island-shaped greenpixel formation sections with the light-shielding sections are removedby polishing from the state of FIG. 20B.

FIG. 21 is an explanatory partial cross-sectional view along the lineXXI-XXI in FIG. 20B.

FIG. 22 is a partial plan view showing the structure of the TFTsubstrate coupled with one of color filters according to third andfourth embodiments of the invention.

FIG. 23A is an explanatory partial cross-sectional view of the TFTsubstrate along the line XXIIIA-XXIIIA in FIG. 22, and FIG. 23B is anexplanatory partial cross-sectional view of the TFT substrate along theline XXIIIB-XXIIIB in FIG. 22.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described indetail below while referring to the drawings attached.

Color Filter of First Embodiment

The structure of a color filter for a LCD device according to a firstembodiment of the present invention is shown in FIGS. 9B, 10A and 11A.

The color filter according to the first embodiment comprises a red colorlayer 1 having the pattern of FIG. 8A, a blue color layer 2 having thepattern of FIG. 8B, and a green color layer 3 having the pattern of FIG.8C. The red, blue, and green color layers 1, 2, and 3 are overlappedwith each other on the surface (i.e., the X-Y plane) of a transparentglass plate (i.e., a transparent support) 9. This color filter does notinclude a black matrix. The light-shielding function of a black matrixis realized by overlapping the red and blue color layers 1 and 2.

The red color layer 1 is formed on the surface of the glass plate 9. Thelayer 1 has stripe-shaped red pixel formation sections 1R and connectionsections 1L, as shown in FIG. 8A.

The stripe-shaped red pixel formation sections 1R are extended along theY direction (vertical direction in FIG. 8A) and arranged along the Xdirection (horizontal direction in FIG. 8A) at predetermined intervals.The sections 1R are used for forming rectangular red pixels arranged inthe Y direction at predetermined intervals. Thus, it may be said thateach of the sections 1R is formed by red pixels and red inter-pixelparts that interconnect the adjoining red pixels.

The connection sections 1L interconnect the adjoining red pixelformation sections 1R. Moreover, the connection sections 1L definerectangular blue pixel windows 1B arranged along the Y direction atpredetermined intervals and rectangular green pixel windows 1G arrangedalong the Y direction at predetermined intervals. Each of the blue pixelwindows 1B is located at a position where a blue pixel is to be formed.Each of the green pixel windows 1G is located at a position where agreen pixel is to be formed.

Accordingly, the red pixels are aligned along the Y direction atpredetermined intervals. The green pixels are aligned along the Ydirection at the same intervals as the red pixels in such a way as to beadjacent to the red pixels. The blue pixels are aligned along the Ydirection at the same intervals as the red pixels in such a way as to beadjacent to the green pixels. This layout or arrangement of the red,green and blue pixels thus aligned is repeatedly aligned along the Xdirection.

The blue color layer 2 is formed on the surface of the glass plate 9 tobe overlapped with the red color layer 1. The layer 2 comprisesstripe-shaped blue pixel formation section 2B and connection sections2L, as shown in FIG. 8B.

The stripe-shaped red pixel formation sections 2B are extended along theY direction and arranged along the X direction at predeterminedintervals. The sections 2B, which are located on such positions as to besuperposed on the corresponding blue pixel windows 1B, are used forforming rectangular blue pixels arranged in the Y direction atpredetermined intervals. Thus, it may be said that each of the sections2B is formed by blue pixels and blue inter-pixel parts that interconnectthe adjoining blue pixels.

The connection sections 2L interconnect the adjoining blue pixelformation sections 2B. Moreover, the connection sections 2L definerectangular red pixel windows 2R arranged along the Y direction atpredetermined intervals and rectangular green pixel windows 2G arrangedalong the Y direction at predetermined intervals. Each of the red pixelwindows 2R is located at a position where a red pixel is to be formed.Each of the green pixel windows 2G is located at a position where agreen pixel is to be formed.

Accordingly, the red pixel windows 2R are located at such positions asto be superposed on the corresponding red pixel formation sections 1R.The green pixel windows 2G are located at such positions as to besuperposed on the corresponding green pixel windows 1G.

A green color layer 3 is formed on the surface of the glass plate 9 tobe overlapped with the red and blue color layers 1 and 2. The layer 3comprises rectangular island-shaped green pixel formation section 3G, asshown in FIG. 8C. These green pixel formation section 3G are formed tobe apart from each other, which are different from the stripe-shapedsections of the color layer 103 of the prior-art color filter. Unlikethe red and blue color layers 1 and 2, the green color layer 3 does nothave connection sections like the connection sections 1L and 2L.

The rectangular island-shaped green pixel formation sections 3G arearranged along the Y direction at predetermined intervals and along theX direction at predetermined intervals. The sections 3G, which arelocated on such positions as to be superposed on the corresponding greenpixel windows 1G of the red color layer 1 and the corresponding greenpixel windows 2G of the blue color layer 2, are used for formingrectangular green pixels arranged in the Y direction at predeterminedintervals. Thus, it may be said that each of the sections 3G is formedby green pixels alone and does not include green inter-pixel parts thatinterconnect the adjoining green pixels.

The color filter of the first embodiment is fabricated by overlappingthe red, blue, and green color layers 1, 2, and 3 with theabove-described patterns in this order. As the fabrication method of thesaid filter, the printing method, photoresist method, etching method, orthe like are known. If the red, blue, and green color layers 1, 2, and 3have the patterns of FIGS. 8A to 8C, respectively, any one of thesemethods may be used. Since the photoresist method is preferred inconsideration of high resolution, good controllability of spectralcharacteristics, and good reproductivity, a fabrication method using thephotoresist method is explained here as an example.

With the photoresist method, a pigment is dispersed in a transparentresin along with an optical initiator, a polymeric monomer and a solventto generate a colored composite. The colored composite thus generated isused as the raw material for the respective color layers. This rawmaterial (i.e., colored material) is coated on the glass plate to form acolored material film. The colored material film thus formed isselectively exposed with a mask and developed, resulting in a colorlayer with a desired pattern. These processes are repeatedly carried outfor the respective colors to fabricate a color filter.

In the case of fabricating the color filter according to the firstembodiment, first, a film of an appropriate red composite (i.e., a redcolored material) is formed on the surface of the glass plate 9 to havea predetermined thickness. The red colored material film is selectivelyexposed with a patterned mask and developed. Thus, the red color layer 1with the pattern of FIG. 8A is formed.

Next, a film of an appropriate blue composite (i.e., a blue coloredmaterial) is formed on the surface of the glass plate 9 to have apredetermined thickness in such a way as to be overlapped with the redcolor layer 1. The blue colored material film is selectively exposedwith a patterned mask and developed. Thus, the blue color layer 2 withthe pattern of FIG. 8B is formed. At this time, as shown in FIG. 9A, theblue pixel formation sections 2B of the blue color layer 2 areoverlapped with the corresponding blue pixel windows 1B of the red colorlayer 1. Moreover, the green pixel windows 2G of the blue color layer 2are overlapped with the corresponding green pixel windows 1G of the redcolor layer 1. The red pixel formation sections 1R of the red colorlayer 1 overlapped with the red pixel windows 2R of the blue color layer2 define red pixels.

Subsequently, a film of an appropriate green composite (i.e., a greencolored material) is formed on the surface of the glass plate 9 to havea predetermined thickness in such a way as to be overlapped with the redand blue color layers 1 and 2. The green colored material film isselectively exposed with a patterned mask and developed. Thus, the greencolor layer 3 with the pattern of FIG. 8C is formed. As a result, thecolor filter of the first embodiment is obtained. The state at thisstage is shown in FIG. 9B. At this time, as shown in FIG. 9B, the greenpixel formation sections 3G of the green color layer 3 are arranged inthe corresponding green pixel windows 1G of the red color layer 1 andthe corresponding green pixel windows 2G of the blue color layer 2overlapped with each other.

As seen from FIG. 9B, the blue pixel formation sections 2B of the bluecolor layer 2 overlapped with the blue pixel windows 1B of the red colorlayer 1 define blue pixels. The green pixel formation sections 3G of thegreen color layer 3 overlapped with the green pixel windows 1G of thered color layer 1 and the green pixel windows 2G of the blue color layer2 define green pixels. Moreover, the connection sections 2L and the blueinter-pixel parts of the blue color layer 2 are overlapped with thecorresponding connection sections 1L or the corresponding redinter-pixel parts of the red color layer 1. The overlapped parts of thered color layer 1 and the blue color layer 2 form light-shieldingsections.

With the color filter according to the first embodiment, as explainedabove, the red pixel formation sections 1R of the red color layer 1 areoverlapped with the red pixel windows 2R of the blue color layer 2,defining the red pixels. The blue pixel formation sections 2B of theblue color layer 2 are overlapped with the blue pixel windows 1B of thered color layer 1, defining the blue pixels. These points are the sameas those of the prior-art color filter of FIGS. 1A to 1C as explainedabove. However, the pattern of the green color layer 3 is different.Specifically, the green color layer 3 has the island-shaped green pixelformation sections 3G alone. Moreover, the green pixel formationsections 3G of the green color layer 3 are overlapped with the greenpixel windows 1G of the red color layer 1 and the green pixel windows 2Gof the blue color layer 2, where the green pixel windows 1G and 2G areoverlapped with each other, defining the green pixels.

Furthermore, the corresponding red inter-pixel parts of thestripe-shaped red pixel formation sections 1R of the red color layer 1and the connection sections 1L thereof are overlapped with thecorresponding connection sections 2L of the blue color layer 2 or theblue inter-pixel parts of the stripe-shaped blue pixel formationsections 2B thereof, forming the light-shielding sections 12. Thelight-shielding sections 12, which have a two-layer structure comprisingthe red color layer 1 and the blue color layer 2 overlapped, have thesame pattern as a black matrix. The green color layer 3, which is notused for the light-shielding sections 12, is patterned to form theisland-shaped green pixel formation sections 3G. The green pixelformation sections 3G are arranged in the overlapped green pixel windows1G and 2G.

The widths of the blue inter-pixel parts of the blue color layer 2 andthe connection sections 2L thereof are slightly larger than the widthsof the red inter-pixel parts of the red color layer 1 and the connectionsections 1L thereof. Therefore, as shown in FIGS. 10A and 11A, the bothedges of the blue inter-pixel parts of the blue color layer 2 and theconnection sections 2L thereof, which are placed on the red inter-pixelparts of the red color layer 1 or the connection sections 1L thereof,are contacted with the surface of the glass plate 9.

The green color layer 3 comprises the rectangular island-shaped greenpixel formation sections 3G alone and does not have green inter-pixelparts like the green color layer 103 (see FIG. 1C) used in the prior-artcolor filter. Thus, as shown in FIGS. 10A and 11A, the green pixelformation sections 3G are approximately fitted in the correspondinggreen pixel windows 1G and 2G and are scarcely overlapped with thelight-shielding sections 12. Therefore, it may be said that thelight-shielding sections 12 even at the positions on which the sections3G are placed have a two-layer structure comprising the red and bluecolor layers 1 and 2. However, in consideration of the possiblealignment errors during the process of forming the red, blue, and greencolor layers 1, 2, and 3, appropriate margins are given to the patternsfor the layers 1, 2, and 3. As a result, the peripheries of the greenpixel formation sections 3G are slightly overlaid on the light-shieldingsections 12 due to the margins. The overlapped parts 10 of the sections3G and 12 caused by the said overlaying may be termed “protruding parts”below. This is because the overlapped parts 10 protrude above thelight-shielding sections 12 and at the same time, the parts 10 arerectangular ring-shaped in such a way as to extend along the peripheriesof the respective green pixels.

The overlapping amount of the overlapped parts 10 between the greenpixel formation sections 3G and the light-shielding sections 12 shouldbe minimized to an extent that optical leakage does not occur due to thealignment errors among the color layers 1, 2, and 3. Concretelyspeaking, it is preferred that the overlapping amount of the overlappedparts 10 is 5.0 μm or less. 3.0 μm or less is more preferred.

Since the green pixel formation sections 3G are aligned along the Ydirection to be adjacent to each other, the adjoining overlapped parts(the protruding parts) 10 are aligned on the light-shielding sections 12in such a way that corresponding inter-color parts 13 intervene betweenthe overlapped parts 10, as shown in FIG. 10A. On the other hand, whatis adjacent to the green pixel formation section 3G along the Xdirection is the red pixel formation section 1R or the blue pixelformation section 2B and therefore, the inter-color parts 13 do notexist along the X direction, as shown in FIG. 11A.

The cross-sectional view of the part including the green pixel along theY direction is shown in FIG. 10A. As seen from FIG. 10A, there is alevel difference “a” between the green pixel (the green pixel formationsection 3G) and the light-shielding section 12 adjoining thereto. Thedifference “a” is approximately equal to the result of subtracting thethickness of the green color layer 3 from the sum of the height of thetwo-layered light-shielding section 12 (which is equal to the sum of thethicknesses of the red and blue color layers 1 and 2) and the height(thickness) of the overlapped part (protruding part) 10. Moreover, thedifference “a” is smaller than the level difference “h” (see FIG. 3A)between the green pixel and the three-layered light-shielding section133 adjoining thereto of the prior-art color filter (i.e., a <h). Thisis because the following reason. Specifically, the light-shieldingsection 133 of the prior-art filter has the three-layer structure. Onthe other hand, with the filter of the first embodiment of theinvention, the overlapped part 10 is simply placed on thelight-shielding section 12 having the two-layer structure, where thethickness of the overlapped part 10 is sufficiently smaller than that ofthe green color layer 3.

The cross-sectional view of the part including the green pixel (thegreen pixel formation section 3G) along the X direction is shown in FIG.11A. As seen from FIG. 11A, there is a level difference “c” between thegreen pixel and the light-shielding section 12 adjoining thereto. Thedifference “c” is equal to the difference “a”. This is because the planshape of the overlapped part 10 is like a rectangular ring.

In this way, with the color filter according to the first embodiment ofthe invention, the level difference “a” (i.e., the level difference “c”)can be made smaller than the level difference h of the prior-art colorfilter over the whole effective display region.

With the color filter according to the first embodiment of theinvention, for example, photo spacers 20 are arranged as shown in FIGS.12A and 12B. Specifically, as shown in FIGS. 12A and 12B, the red, blueand green color layers 1, 2 and 3 are overlapped in this order on thesurface of the glass plate 9. An overcoat layer 23 is formed on thegreen color layer 3. The overcoat layer 23 covers the color layers 1, 2and 3 over the whole effective display region. At the positions locatedover the light-shielding sections 12 right over the correspondinginter-color parts 13 of the green pixel formation sections 3G, thespacers 20 are formed to have a rectangular (belt-like) plan shape. Thismeans that the spacers 20 are formed in such a way as to bury or fillthe whole corresponding inter-color parts 13. The width (the lengthalong the Y direction) of the spacers 20 is slightly smaller than thatof the light-shielding section 12. The length (the length along the Xdirection) of the spacers 20 is approximately equal to that of the greenpixel formation section 3G. These spacers 20 are formed by patterning aknown photoresist (photosensitive resin) film.

By forming the photo spacers 20 in the above-described way, theoverlapped parts (protruding parts) 10 of the green pixel formationsections 3G on the light-shielding sections 12 are embedded or absorbedin the corresponding spacers 20. Therefore, almost all the bad effectsinduced by the overlapped parts 10 can be eliminated. In other words,the light-shielding sections 12 have a structure like a three-layeredone due to existence of the overlapped parts 10; however, the height(thickness) of the overlapped parts 10 is included or absorbed in theheight of the spacers 20. Therefore, the resultant structure will beapproximately the same structure as that the overlapped parts 10 areomitted.

FIG. 14 shows the state where the TFT substrate 26 is coupled with thecolor filter of the first embodiment having the structure of FIGS. 12Aand 12B. As clearly seen from FIG. 14, the cell gap “a” is equal to thesum of the height of the photo spacers 20 and the level difference “f”.However, the difference “f” is smaller than the difference “h” of theprior-art filter (i.e., f<h). Thus, there is an advantage that theheight of the spacers 20 can be increased by the difference between “h”and “f”.

By the way, with the color filter of the first embodiment, theoverlapped parts 10 can be removed by polishing to avoid the effects ofthe parts 10. It is more preferred that the overlapped parts 10 areremoved. This is easily realized by polishing the whole surface of theglass plate 9 with a known polishing apparatus, because the parts 10 arerectangular ring-shaped and the gross area of the parts 10 is by farsmaller than that of the prior-art color filter.

The cross-sectional structure of the color filter after the overlappedparts 10 are removed is shown in FIGS. 9C, 10B, and 11B. In this case,since the parts 10 do not exist, the level differences “b” and “d” aresmaller than the level differences “a” and “c”, respectively. Thus, thisis more preferred than the case including the parts 10. However, thereis a disadvantage that the polishing process for removing the parts 10is added. Accordingly, when the small level difference is important, itis preferred to remove the parts 10 by polishing. On the other hand,when the fabrication cost is important, it is preferred not to removethe parts 10. In addition, the difference “d” is equal to the difference“b”.

FIG. 13A shows an example of the arrangement of the photo spacers 20,where the overlapped parts 10 of the sections 3G on the light-shieldingsections 12 are removed by polishing. In this case, since the parts 10do not exist on the light-shielding sections 12, and the green pixelformation sections 3G are fitted in the green pixel windows 1G and 2G,the vicinity of the spacer 20 has the cross-sectional structure shown inFIG. 13B. As seen from FIG. 13B, the level difference “g” between thegreen pixels (the green pixel formation sections 3G) and thelight-shielding sections 12 is equal to the subtraction result of theheight of the sections 12 from the thickness of the overlapped parts 10.

In the example of FIG. 13A, since the overlapped parts 10 and theinter-color parts 13 do not exist on the light-shielding sections 12, itis unnecessary that the photo spacers 20 are formed belt-shaped to coverthe whole overlapped parts 10 (i.e., the inter-color parts 13), as shownin FIG. 12A. This means that the freedom of arrangement of the spacers20 is very high. Accordingly, for example, the spacers 20 may be formedbar- or columnar-shaped to cover only the very narrow areas near thesections 12, as shown in FIG. 13A.

FIG. 15 shows the state where the TFT substrate 26 is coupled with thecolor filter of the first embodiment without the overlapped parts 10. Asclearly seen from FIG. 15, the cell gap “b” is equal to the sum of theheight of the photo spacers 20 and the level difference “g”. However,the difference “g” is smaller than the difference “f” of the caseincluding the parts 10 (i.e., g<f). Thus, there is an advantage that theheight of the spacers 20 can be increased by the difference between “f”and “g”.

The level difference “f” or “g” needs to be a value that does not giveany bad effects. The level difference “f” or “g” needs to be 3.0 μm orless. Preferably, the level difference “f” or “g” is 1.5 μm or less byplanarizing by way of, for example, adjusting the thickness of theovercoat layer 23.

With the color filter according to the first embodiment of theinvention, as explained above in detail, the red color layer 1 havingthe shape or pattern of FIG. 8A, the blue color layer 2 having the shapeor pattern of FIG. 8B, and the green color layer 3 having the shape orpattern of FIG. 8C are formed to be overlapped with each other on theglass plate 9. The overlapped parts 10 of the red color layer 1 and theblue color layer 2 function as the light-shielding sections 12.Therefore, a black matrix for forming the light-shielding sections 12 isunnecessary.

The green pixel formation sections 3G of the green color layer 3 areisland-shaped apart from each other. Moreover, the sections 3G arearranged in the green pixel windows 1G of the red color layer 1 and thegreen pixel windows 2G of the blue color layer 2 overlapped with eachother, defining the green pixels. Therefore, by appropriately adjustingthe size of the green pixel formation sections 3G, the sections 3G canbe scarcely placed on the overlapped parts 10 of the red and blue colorlayers 1 and 2 having the function of the light-shielding sections 12.This means that the level difference between the light-shieldingsections 12 and the red, blue or green color layer 1, 2, or 3 or pixels(i.e., the colored materials that form the pixels of the respectivecolors) can be reduced. In addition, such the reduction of the leveldifference can be realized by an easy method. This is because thereduction of the level difference between the light-shielding sections12 and the red, blue or green color layer 1, 2, or 3 or pixels can beobtained by making the green pixel formation sections 3G of the greencolor layer 3 island-shaped to be apart from each other.

Moreover, by appropriately adjusting the size of the green pixelformation sections 3G (which are not used for forming thelight-shielding sections 12), the sections 3G can be arranged on theglass plate 9 in such a way that the peripheries of the sections 3G arescarcely placed on the overlapped parts 10 of the red and green colorlayers 1 and 2 that provide the light-shielding function. Therefore, theamount of the green layer 3 (i.e., the sections 3G) placed on thelight-shielding sections 12 is limited to a small value. As a result,the sections 3G placed on the light-shielding sections 12 can be easilyremoved by polishing.

Furthermore, it is sufficient that the red and blue color layers 1 and 2are respectively formed to have the stripe-shaped red and blue pixelformation sections 1R and 2B and the connection sections 1L and 2L, andthat the green color layer 3 is formed to have the island-shaped pixelformation sections 3G. Therefore, the patterning process of therespective color layers (i.e., the red, blue, and green color layers 1,2 and 3) to obtain a desired light-shielding performance can beconducted easily.

In addition, with the above-described color filter according to thefirst embodiment, the light-shielding sections 12 have the two-layerstructure comprising the red and blue color layers 1 and 2. This isbecause this combination minimizes the optical transmittance (in otherwords, it maximizes the OD value). Since the sections 12 may include thered and blue color layers 1 and 2, the blue color layer 2 may beoverlaid on the red color layer 1 as explained above or the red colorlayer 1 may be overlaid on the blue color layer 2.

Here, the above-described first embodiment of the invention refers tothe case that the light-shielding sections 12 are “inter-pixellight-shielding sections”. However, the light-shielding sections 12 areapplicable to the “TFT light-shielding sections” located to be oppositeto the TFTs, and the “frame area” that is placed outside the effectivedisplay area and that surrounds the effective display area.

LCD Device of First Embodiment

An LCD device according to the first embodiment of the inventioncomprises the TFT substrate 26 having any structure. Here, the structureof the IPS type shown in FIGS. 16, 17, 18A and 18B is used. Thisstructure is approximately the same as that illustrated in FIGS. 1 to 3of the Japanese Non-Examined Patent Publication No. 2005-241923. ThisLCD device is designed to operate in the normally black mode.

FIG. 16 is a partial plan view showing the structure of the TFTsubstrate 26 coupled with the color filter according to the firstembodiment. FIG. 17 shows the cross-sectional structure of the devicealong the line XVII-XVII in FIG. 16. FIG. 18A shows the cross-sectionalstructure of the TFT substrate along the line XVIIIA-XVIIIA in FIG. 16.FIG. 18B shows the cross-sectional structure of the TFT substrate alongthe line XVIIIB-XVIIIB in FIG. 16.

As shown in FIG. 16, the TFT substrate 26 comprises a common electrodeline 43 made of metal, a contact hole 45 for a common electrode, acomb-teeth-shaped transparent common electrode 46, a field-shieldingsection 46a of the common electrode 46 which shields the leaked electricfield from the TFT 51, a comb-teeth-shaped transparent pixel electrode47, a contact hole 48 for the pixel electrode 47, a scanning line 49, adata line 50, a TFT 51, a source electrode 52 of the TFT 51, a drainelectrode 53 of the TFT 51, an island-shaped a-Si film 54 for forming anactive layer of the TFT 51, and a pixel auxiliary electrode 56.

The pixel electrode 47 has three zigzag-shaped comb teeth. The commonelectrode 46 has four zigzag-shaped comb teeth. The pixel electrode 47and the common electrode 46 are arranged in such a way as to bealternately engaged with each other in the region surrounded by theadjoining scanning lines 49 and the adjoining data lines 50. The twoteeth of the common electrode 46 at its each side are overlapped withthe corresponding data lines 50, respectively. The pixel auxiliaryelectrode 56 has one comb tooth superposed on the central tooth of thepixel electrode 47.

Each of the data lines 50 is electrically connected to the drainelectrode 53 of a corresponding one of the TFTs 51. Each of the scanninglines 49 is electrically connected to the gate electrode (not shown) ofa corresponding one of the TFTs 51. Each of the pixel electrodes 47 iselectrically connected to the source electrode of a corresponding one ofthe TFTs 51 by way of a corresponding one of the contact holes 48, asshown in FIG. 18A. Each of the common electrodes 46 is electricallyconnected to a corresponding one of the common electrode lines 43 by wayof a corresponding one of the contact holes 45, as shown in FIG. 18B.

As shown in FIGS. 17, 18A and 18B, the scanning lines 49 and the commonelectrode lines 43 are formed by patterning a first metal film (e.g., Crfilm or Al alloy film) formed on a transparent plate 61. The first metalfilm is covered with a first interlayer insulating flayer 62 that servesas the gate insulating films of the TFTs 51.

The island-shaped a-Si films 54 are formed on the first interlayerinsulating flayer 62. The pixel auxiliary electrodes 56, the data lines50, and the source and drain electrodes 52 and 53 are formed bypatterning a second metal film (e.g., Cr film or Al alloy film) formedon the first interlayer insulating flayer 62. The source and drainelectrodes 52 and 53 are contacted with each end of a corresponding oneof the a-Si films 54. The a-Si films 54, the pixel auxiliary electrodes56, the data lines 50, and the source and drain electrodes 52 and 53 arecovered with a second interlayer insulating layer (e.g., an organic filmor silicon nitride film) 63.

The pixel electrodes 47 and the common electrodes 46 are formed bypatterning a transparent conductive film (e.g., ITO film) formed on athird interlayer insulating layer 64. The third interlayer insulatinglayer 64 is formed on the second interlayer insulating layer 63. Thepixel electrodes 47 and the common electrodes 46, each of which haszigzag-shaped comb teeth, are arranged in such a way as to bealternately engaged with each other and to be apart from each other onthe third interlayer insulating layer 64. Responsive to this, the partsof the data lines 50 adjoining to the corresponding pixel electrodes 47are bent in zigzag.

The field-shielding sections 46a of the common electrodes 46 areprovided to prevent the leaked electric field from the scanning lines 49and the data lines 50 from applying to the liquid-crystal layer 80 (inother words, shielding the leaked electric field). The sections 46a arepatterned in such a way as to protrude or partially cover the scanningand data lines 49 and 50 on the third interlayer insulating layer 64. Byshielding the leaked electric field from the TFT substrate 26 with thefield-shielding sections 46a, the amount of electrification of the red,blue and green color layers 1, 2, and 3 can be decreased. Therefore, thedefective orientation of the liquid-crystal molecules (e.g.,disclination) is suppressed or avoided and as a result, display defectssuch as color irregularity can be prevented.

In addition, a polarizer 66 is attached to the outer surface of thetransparent plate 61 of the TFT substrate 26.

The LCD device according to the first embodiment of the inventioncomprises the above-described TFT substrate 26, the opposite substrate70, and the liquid-crystal layer 80 sandwiched by the substrates 26 and70, as shown in FIG. 17.

The opposite substrate 70 comprises a color filter 72 formed on atransparent plate 71 (i.e., the glass plate 9), an overcoat layer 73formed on the color filter 72, an alignment layer 74 formed on theovercoat layer 73, a conductive layer 75 formed on the outer surface ofthe plate 71, and a polarizer 76 formed on the conductive layer 75. Thecolor filter of the first embodiment corresponds to the color filter 72.The glass plate 9 and the overcoat layer 23 of the color filter of thefirst embodiment correspond to the glass plate 71 and the overcoat layer73, respectively.

Since the data lines 50 of the TFT substrate 26 are formed by patterningthe second metal film, as described above, the backlight irradiatedtoward the data lines 50 is shielded by the data lines 50. However, theexternal light and the reflected light of the external light by themetal wiring lines on the TFT substrate 26 needs to be shielded by thelight-shielding sections on the color filter. With the color filter ofthe first embodiment, to meet this need, the light-shielding function isaccomplished by the two-layered light-shielding sections 12 comprisingthe red and blue color layers 1 and 2.

Moreover, with the TFT substrate 26, as shown in FIG. 16, slits arepresent between the common electrode lines 43 and the correspondingscanning lines 49 in the vicinities of the scanning lines 49, wherethese lines 43 and 49 made of opaque metal. Thus, the backlightirradiated toward these regions is unable to be shielded completely bythe common electrode lines 43 and the scanning lines 49 alone. To shieldthe light penetrating through the slits, the field-shielding sections46a of the transparent common electrodes 46 are formed to cover theseslits. As a result, the field-shielding sections 46a are overlapped withthe slits and therefore, the light penetrating through the slits can besurely shielded. This is because in the regions of the liquid-crystallayer 80 corresponding to the field-shielding sections 46a, the leakedelectric field is shielded by the sections 46a and thus, the liquidcrystal molecules in the liquid-crystal layer 80 are not driven.Consequently, the light penetrating through the slits from the backlightunit can be shielded by the polarizers 66 and 67 in the normally blackmode.

However, with the TFT substrate 26, to decrease the effect of thesections 46a to the TFTs 51, the field-shielding sections 46a of thecommon electrodes 46 are formed not to overlap with the TFTs 51. This isdue to the following reason: If the sections 46a are overlapped with theTFTs 51, the electric-field shielding effect of the sections 46aincreases. In this case, however, there is a high possibility that thesections 46a gives a bad effect to the operation characteristics of theTFTs 51 if the thickness of the second and third interlayer insulatinglayers 63 and 64 fluctuates to the smaller side due to errors occurringduring the fabrication processes. Accordingly, the sections 46a forshielding the electric field leaked from the scanning lines 49 arepatterned to avoid the TFTs 51, thereby widening the safety margin.

In this way, by the field-shielding sections 46a of the commonelectrodes 46, application of the electric field to the liquid crystalmolecules in the vicinities of the scanning lines 49 is prevented and atthe same time, the light passing through these regions is shielded.Moreover, the external light and the reflected light of the externallight by the metal wiring lines on the TFT substrate 26 are shielded bythe two-layered light-shielding sections 12 on the color filter.

As explained above, the LCD device according to the first embodiment ofthe invention comprises the above-described color filter of the firstembodiment and the TFT substrate 26 shown in FIGS. 16, 17, and 18A and18B and therefore, a desired light-shielding function can be realizedwithout a black matrix. As a result, high contrast and good colorreproductivity can be obtained and at the same time, high-speed responsecharacteristics can be obtained because a narrower gap than that of theprior-art LCD devices is realized.

Color Filter of Second Embodiment

The structure of a color filter for a LCD device according to a secondembodiment of the present invention is shown in FIG. 20B. FIG. 20B is apartial plan view of the said color filter.

The color filter according to the second embodiment comprises a redcolor layer 1a having the pattern of FIG. 19A, a blue color layer 2ahaving the pattern of FIG. 19B, and a green color layer 3a having thepattern of FIG. 19C. The red, blue, and green color layers 1a, 2a, and3a are overlapped on the surface (i.e., the X-Y plane) of a transparentglass plate (i.e., a transparent support) 9. This color filter does notinclude a black matrix. This point is the same as the above-describedcolor filter according to the first embodiment. However, the colorfilter according to the second embodiment is different from that of thefirst embodiment in that (i) the light-shielding function in thevicinities of the scanning lines on the TFT substrate is realized byoverlapping the red and blue color layers 1a and 2a, and that (ii) thelight-shielding function in the vicinities of the data lines on the TFTsubstrate is realized by overlapping the two color layers adjacent toeach other (i.e., by overlapping the red and blue color layers 1a and2a, the blue and green color layers 2a and 3a, and the green and redcolor layers 3a and 1a).

The red color layer 1a is formed on the surface of the glass plate 9.The layer 1a has stripe-shaped red pixel formation sections 1Ra andconnection sections 1La, as shown in FIG. 19A.

The stripe-shaped red pixel formation sections 1Ra are extended alongthe Y direction and arranged along the X direction at predeterminedintervals. The sections 1Ra are used for forming rectangular red pixelsarranged in the Y direction at predetermined intervals. Thus, it may besaid that each of the sections 1Ra is formed by red pixels and redinter-pixel parts that interconnect the adjoining red pixels.

The connection sections 1La interconnect the adjoining red pixelformation sections 1Ra. Moreover, the connection sections 1La definerectangular blue-and-green pixel windows 1BGa arranged along the Ydirection at predetermined intervals. Each of the blue-and-green pixelwindows 1BGa is located at a position where a blue pixel and a greenpixel adjacent thereto are to be formed. Each of the blue-and-greenpixel windows 1BGa is formed by a rectangular blue pixel subwindow1BGa-B covered with the blue color layer 2a when the blue color layer 2ais overlapped, and a rectangular green pixel subwindow 1BGa-G notcovered with the blue color layer 2a even when the blue color layer 2ais overlapped.

Accordingly, the red pixels are aligned along the Y direction atpredetermined intervals. The green pixels are aligned along the Ydirection at the same intervals as the red pixels in such a way as to beadjacent to the red pixels. The blue pixels are aligned along the Ydirection at the same intervals as the red pixels in such a way as to beadjacent to the green pixels. The layout of the red, green and bluepixels thus aligned is repeatedly aligned along the X direction. Thispoint is the same as the first embodiment.

The blue color layer 2a is formed on the surface of the glass plate 9 tobe overlapped with the red color layer 1a. The layer 2a hasstripe-shaped blue pixel formation sections 2Ba and connection sections2La, as shown in FIG. 19B.

The stripe-shaped blue pixel formation sections 2Ba are extended alongthe Y direction and arranged along the X direction at predeterminedintervals. The sections 2Ba are used for forming rectangular blue pixelsarranged in the Y direction at predetermined intervals. Each of thesections 2Ba is located at a position to be overlapped with the bluepixel subwindow 1BGa-B of the corresponding blue-and-green pixel window1BGa to the red color layer 1a. Thus, it may be said that each of thesections 2Ba is formed by blue pixels and blue inter-pixel parts thatinterconnect the adjoining blue pixels.

The connection sections 2La interconnect the adjoining blue pixelformation sections 2Ba. Moreover, the connection sections 2La definerectangular red-and-green pixel windows 2RGa arranged along the Ydirection at predetermined intervals. Each of the red-and-green pixelwindows 2RGa is located at a position where a set of a red pixel and agreen pixel adjoining to each other is to be formed. Each of thered-and-green pixel windows 2RGa is formed by a rectangular green pixelsubwindow 2RGa-G covered with the green color layer 3a when the greencolor layer 3a is overlapped, and a rectangular red pixel subwindow2RGa-R not covered with the green color layer 3a even when the greencolor layer 3a is overlapped.

The green color layer 3a is formed on the surface of the glass plate 9to be overlapped with the red and blue color layers 1a and 2a. The layer3a has rectangular island-shaped green pixel formation sections 3Ga, asshown in FIG. 19C. The green pixel formation sections 3Ga are formed tobe apart from each other, which are not stripe-shaped like the prior-artcolor filter. Moreover, unlike the red and blue color layers la and 2a,the layer 3a does not comprise any connection sections like theconnection sections 1La and 2La.

The rectangular island-shaped green pixel formation sections 3Ga arearranged not only along the Y direction at predetermined intervals butalso along the X direction at predetermined intervals. The sections 3Gaare used for forming rectangular green pixels arranged in the X and Ydirections at predetermined intervals. Each of the sections 3Ga islocated at a position to be overlapped with the green pixel subwindow1BGa-G of the corresponding blue-and-green pixel window 1BGa to the redcolor layer 1a, and the green pixel subwindow 2RGa-G of thecorresponding red-and-green pixel window 2RGa to the blue color layer2a. Thus, it may be said that each of the sections 3Ga is formed by thegreen pixels alone and that it comprises no green inter-pixel parts thatinterconnect the adjoining green pixels.

The color filter of the second embodiment is fabricated by overlappingthe red, blue, and green color layers 1a, 2a, and 3a with theabove-described patterns in this order. If the red, blue, and greencolor layers 1a, 2a, and 3a have the patterns of FIGS. 19A to 19C,respectively, any one of the printing, photoresist and etching methodsmay be used. Here, a fabrication method using the photoresist method isexplained below.

First, a film of an appropriate red composite (i.e., a red coloredmaterial) is formed on the surface of the glass plate 9 to have apredetermined thickness. The red colored material film thus formed isselectively exposed with a patterned mask and developed. Thus, the redcolor layer la with the pattern of FIG. 19A is formed.

Next, a film of an appropriate blue composite (i.e., a blue coloredmaterial) is formed on the surface of the glass plate 9 to have apredetermined thickness in such a way as to be overlapped with the redcolored layer 1a. The blue colored material film thus formed isselectively exposed with a patterned mask and developed. Thus, the bluecolor layer 2a with the pattern of FIG. 19B is formed. At this time, asshown in FIG. 20A, the blue pixel formation sections 2Ba of the bluecolor layer 2a are overlapped with the corresponding blue pixelsubwindows 1BGa-B of the blue-and-green pixel window 1BGa of the redcolor layer 1a. The red pixel subwindows 2RGa-R of the red-and-greenpixel windows 2RGa of the blue color layer 2a are overlapped with thered pixel formation sections 1Ra of the red color layer 1a. The greenpixel subwindows 2RGa-G of the red-and-green pixel windows 2RGa of theblue color layer 2a are overlapped with the green pixel subwindows1BGa-G of the blue-and-green pixel windows 1BGa of the red color layer1a.

Subsequently, a film of an appropriate green composite (i.e., a greencolored material) is formed on the surface of the glass plate 9 to havea predetermined thickness in such a way as to be overlapped with the redand blue color layers 1a and 2a. The green colored material film thusformed is selectively exposed with a patterned mask and developed. Thus,the green color layer 3a with the pattern of FIG. 19C is formed. As aresult, the color filter of the second embodiment is obtained. The stateat this stage is shown in FIG. 20B. At this time, the island-shapedgreen pixel formation sections 3Ga of the green color layer 3a arearranged in the corresponding green pixel subwindows 1BGa-G of theblue-and-green pixel windows 1BGa of the red color layer 1a and thecorresponding green pixel subwindows 2RGa-G of the red-and-green pixelwindows 2RGa of the blue color layer 2a overlapped with each other. Thegreen pixel subwindows 1BGa-G and 2RGa-G are overlapped with each other.

As seen from FIG. 20B, the red pixels are defined by the red pixelformation sections 1Ra of the red color layer 1a, the red-and-greenpixel windows 2RGa of the blue color layer 2a overlapped with the redpixel formation sections 1Ra, and the green pixel formation sections 3Gaof the green color layer 3a overlapped with the red and blue colorlayers 1a and 2a. The blue pixels are defined by the blue pixelformation sections 2Ba of the blue color layer 2a, the blue-and-greenpixel windows 1BGa of the red color layer 1a overlapped with the bluepixel formation sections 2Ba, and the green pixel formation sections 3Gaof the green color layer 3a overlapped with the red and blue colorlayers 1a and 2a. The green pixels are defined by the green pixelformation sections 3Ga of the green color layer 3a, the blue-and-greenpixel windows 1BGa of the red color layer 1a overlapped with the bluecolor layer 2a, and the red-and-green pixel windows 2RGa of the bluecolor layer 2a overlapped with the red and blue color layers 1a and 2a.

The connection sections 2La and the blue inter-pixel parts of the bluecolor layer 2a, both of which are extended along the X direction, areoverlapped with the connection sections 1La or the red inter-pixel partsof the red color layer 1a extending along the X direction. Theoverlapped parts of the red color layer 1a and the blue color layer 2aform the light-shielding sections similar to those in the firstembodiment. This means that the overlapped parts of the red and bluecolor layers 1a and 2a that extend along the X direction form thelight-shielding sections extending along the X direction (i.e., theX-direction light-shielding sections). Since these X-directionlight-shielding sections have the two-layer structure comprising the redand blue color layers 1a and 2a, which is the same as that of thelight-shielding sections 12 in the color filter of the first embodiment,the same reference symbol 12 is attached to the said light-shieldingsections below. The X-direction light-shielding sections 12 are used tolight-shield the regions corresponding to the scanning lines 49 (whichare extended along the X direction) of the TFT substrate 26a (see FIG.22) explained later.

The red pixel formation sections 1Ra of the red color layer 1a and thegreen pixel formation sections 3Ga of the green color layer 3a adjacentthereto are overlapped with each other at their both sides along the Ydirection, thereby forming the light-shielding sections 18 along the Ydirection (i.e., the red-and-green Y-direction light-shieldingsections), as shown in FIG. 21. In other words, the light-shieldingoperation in the regions intervening between the adjoining red and greenpixels along the X direction is carried out by the red-and-greenY-direction light-shielding sections 18 having the two-layer structureof the red and green color layers 1a and 3a.

Similarly, the green pixel formation sections 3Ga of the green colorlayer 3a and the blue pixel formation sections 2Ba of the blue colorlayer 2a adjacent thereto are overlapped with each other at their bothsides along the Y direction, thereby forming the light-shieldingsections 19 along the Y direction (i.e., the green-and-blue Y-directionlight-shielding sections), as shown in FIG. 21. In other words, thelight-shielding operation in the regions intervening between theadjoining green and blue pixels along the X direction is carried out bythe green-and-blue Y-direction light-shielding sections 19 having thetwo-layer structure of the green and blue color layers 3a and 2a.

The blue pixel formation sections 2Ba of the blue color layer 2a and thered pixel formation sections 1Ra of the red color layer 1a adjacentthereto are overlapped with each other at their both sides along the Ydirection, thereby forming the light-shielding sections along the Ydirection (i.e., the blue-and-red Y-direction light-shielding sections).(Since this structure is the same as that of light-shielding sections19, illustration is omitted.) In other words, the light-shieldingoperation in the regions intervening between the adjoining blue and redpixels along the X direction is carried out by the blue-and-redY-direction light-shielding sections having the two-layer structure ofthe bleu and red color layers 2a and 1a.

The red-and-green Y-direction light-shielding sections 18, thegreen-and-blue Y-direction light-shielding sections 19, and theblue-and-red Y-direction light-shielding sections are used tolight-shield the regions corresponding to the data lines 50 (whichextend along Y direction) of the TFT substrate 26 (see FIGS. 16, 17, 18Aand 18B).

With the color filter according to the second embodiment, as explainedabove, the X-direction light-shielding sections 12 for light-shieldingthe regions corresponding to the scanning lines 49 of the TFT substrate26 have the two-layer structure comprising the red and blue color layers1a and 2a, which is the same as the light-shielding sections 12 in thefirst embodiment. On the other hand, the red-and-green Y-directionlight-shielding sections 18, the green-and-blue Y-directionlight-shielding sections 19, and the blue-and-red Y-directionlight-shielding sections for light-shielding the regions correspondingto the data lines 50 of the TFT substrate 26 have the two-layerstructures comprising the red and green color layers 1a and 3a, thegreen and blue color layers 3a and 2a, and the blue and red color layers2a and 1a, respectively. These Y-direction light-shielding sections maybe termed the “adjoining-color overlapped light-shielding sections”.This is because each of these three types of the light-shieldingsections is formed by overlapping the colored materials for twoadjoining pixels with each other. The combination of the X-directionlight-shielding sections 12, the red-and-green Y-directionlight-shielding sections 18, the green-and-blue Y-directionlight-shielding sections 19, and the blue-and-red Y-directionlight-shielding sections defines the same pattern as the black matrix.Therefore, they realize the same light-shielding function as the blackmatrix.

The widths of the blue inter-pixel parts of the blue color layer 2a andthe connection sections 2La thereof are slightly larger than the widthsof the red inter-pixel parts of the red color layer 1a and theconnection sections 1La thereof. Therefore, similar to the firstembodiment shown in FIGS. 11A and 12A, the both edges of the blueinter-pixel parts of the blue color layer 2a and the connection sections2La thereof, which are placed on the red inter-pixel parts of the redcolor layer 1a or the connection sections 1La thereof, are contactedwith the surface of the glass plate 9.

The green color layer 3a comprises the rectangular island-shaped greenpixel formation sections 3Ga alone. Thus, like the first embodimentshown in FIGS. 11A, the green pixel formation sections 3Ga areapproximately fitted in the green pixel subwindows 1BGa-G of thecorresponding blue-and-green pixel windows 1BGa and the green pixelsubwindows 2RGa-G of the corresponding red-and-green pixel windows 2RGa.In other words, the sections 3Ga are scarcely overlapped with theX-direction light-shielding sections (which correspond to thelight-shielding sections 12 shown in 11A) in the Y direction. Therefore,it may be said that the X-direction light-shielding sections 12 even atthe positions on which the sections 3Ga are placed have a two-layerstructure comprising the red and blue color layers 1a and 2a.

However, in consideration of the possible alignment errors during theprocess of forming the red, blue, and green color layers 1a, 2a, and 3a,appropriate margins are given to the patterns for the layers 1a, 2a, and3a. As a result, the peripheries of the green pixel formation sections3Ga are slightly overlaid on the X-direction light-shielding sections 12due to the margins. The overlapped parts of the sections 3Ga and 12caused by the said overlying protrude above the X-directionlight-shielding sections 12.

In addition, the said overlapped parts are linear (belt-shaped) in sucha way as to extend along the edges of the respective green pixels alongthe X direction, which are not rectangular ring-shaped. This is becausethe edges of the respective green pixels along the Y direction areplaced on the red or blue color layer 1a or 2a and never placed on thetwo-layer structure comprising the layers 1a and 2a.

The cross-sectional view of the part including the green pixel (thegreen pixel formation section 3Ga) along the Y direction is the same asthe first embodiment shown in FIG. 10A. There is a level difference “a”between the green pixel and the X-direction light-shielding section 12adjoining thereto. The level difference “a” is smaller than the leveldifference “h” (see FIG. 3A) between the green pixel and thethree-layered light-shielding section 133 adjoining thereto of theprior-art color filter (i.e., a<h).

The cross-sectional view of the part including the green pixel (thegreen pixel formation section 3Ga) along the X direction is shown inFIG. 21A, which is different from the first embodiment. The reason isapparent from FIG. 21A. Specifically, the left-side light-shieldingsection (i.e., the Y-direction light-shielding section) 18 has atwo-layer structure of the red and green color layers 1a and 3a, becausethe red pixel is adjacent to the said green pixel on its left side. Theright-side light-shielding section (i.e., the Y-directionlight-shielding section) 19 has a two-layer structure of the blue andgreen color layers 2a and 3a, because the blue pixel is adjacent to thesaid green pixel on its right side. In addition, there is a leveldifference “e” between the said green pixel and the Y-directionlight-shielding section 18 or 19 adjoining thereto. The difference “e”is smaller than the level difference “a” (e<a). This is because theY-direction light-shielding section 18 or 19 has a two-layer structureon which no protruding part exists.

In this way, with the color filter according to the second embodiment,the level difference “a” in the Y-direction cross section can be madesmaller than the level difference “h” of the prior-art color filter overthe whole effective display region. Moreover, the level difference “e”in the X-direction cross section can be made smaller than the leveldifference “e”.

With the color filter according to the second embodiment of theinvention also, the photo spacers 20 are formed. Since the arrangementof the spacers 20 is the same as the first embodiment, the explanationabout it is omitted here.

To eliminate the effect of the overlapped parts (protruding parts) onthe green pixel formation sections 3Ga, the overlapped parts may beremoved by polishing. It is preferred that the overlapped parts areremoved by polishing. With the color filter of the second embodiment,the overlapped parts are linear (belt-shaped) along the edges of thesections 3Ga in the X direction, and the gross area of the overlappedparts is less than that of the color filter of the first embodiment.Therefore, by polishing the whole surface of the glass plate 9 with aknown polishing apparatus, removal of the overlapped parts can berealized more easily.

The state after the overlapped parts are removed by polishing is shownin FIG. 20C. The cross-sectional structure along the Y direction is thesame as that shown in FIG. 10B for the first embodiment. Thecross-sectional structure along the X direction is the same as thatshown in FIG. 21.

The arrangement of the photo spacers 20 in the case where the overlappedparts of the sections 3G are removed is the same as that of the firstembodiment.

With the color filter according to the second embodiment of theinvention, as explained in detail, the red color layer 1a having theshape or pattern of FIG. 19A, the blue color layer 2a having the shapeor pattern of FIG. 19B, and the green color layer 3a having the shape orpattern of FIG. 19C are formed on the glass plate 9 to be overlapped.Moreover, the X-direction light-shielding sections 12 forlight-shielding the regions corresponding to the scanning lines 49 ofthe TFT substrate 26 have the two-layer structure comprising the red andblue color layers 1a and 2a. The red-and-green Y-directionlight-shielding sections 18, the green-and-blue Y-directionlight-shielding sections 19, and the blue-and-red Y-directionlight-shielding sections for light-shielding the regions correspondingto the data lines 50 of the TFT substrate 26 have the two-layerstructures comprising the red and green color layers 1a and 3a, thegreen and blue color layers 3a and 2a, and the blue and red color layers2a and 1a, respectively. The combination of the X-directionlight-shielding sections 12, the red-and-green Y-directionlight-shielding sections 18, the green-and-blue Y-directionlight-shielding sections 19, and the blue-and-red Y-directionlight-shielding sections functions as the black matrix. Therefore, ablack matrix is unnecessary.

The green pixel formation sections 3Ga of the green color layer 3a,which define the green color pixels by the overlapping with theblue-and-green pixel windows 1BGa of the red color layer 1a and thered-and-green pixel windows 2RGa of the blue color layer 2a, areisland-shaped apart from each other. Therefore, by appropriatelyadjusting the size of the green pixel formation sections 3Ga, thesections 3Ga can be scarcely placed on the overlapped parts of the redand blue color layers 1a and 2a having the function of the X-directionlight-shielding sections 12. This means that the level differencebetween the X-direction light-shielding sections 12 and the red, blue orgreen pixels can be reduced. In addition, such the reduction of thelevel difference can be realized by an easy method. This is because thereduction of the level difference between the X-directionlight-shielding sections 12 and the red, blue or green pixels can beobtained by making the sections 3Ga of the green color layer 3aisland-shaped to be apart from each other.

Moreover, by appropriately adjusting the size of the green pixelformation sections 3Ga of the green color layer 3a, the sections 3Ga canbe arranged on the glass plate 9 in such a way that the peripheries ofthe sections 3Ga are scarcely placed on the overlapped parts of the redand blue color layers 1a and 2a that provide the function of theX-direction light-shielding sections 12. Therefore, the amount of thegreen color layer 3a (i.e., the green pixel formation sections 3Ga)placed on the X-direction light-shielding sections 12 is limited to asmall value. As a result, the sections 3Ga placed on the X-directionlight-shielding sections 12 can be easily removed by polishing.

Furthermore, it is sufficient for the invention that the red and bluecolor layers 1a and 2a are respectively formed to have the stripe-shapedpixel formation sections 1R and 2B and the blue-and-green pixel windows1BGa or the red-and-green pixel windows 2RGa, and that the green colorlayer 3a is formed to have the island-shaped pixel formation sections3Ga. Therefore, the patterning process of the respective color layers1a, 2a, and 3a to obtain a desired light-shielding performance can beconducted easily.

In addition, with the color filter according to the second embodiment,the X-direction light-shielding sections 12 have the two-layer structurecomprising the red and blue color layers 1a and 2a. This is because thiscombination minimizes the optical transmittance (in other words, itmaximizes the OD value). Since the sections 12 may include the red andblue color layers 1a and 2a, the blue color layer 2a may be overlaid onthe red color layer 1a as explained above or the red color layer 1a maybe overlaid on the blue color layer 2a.

Here, the above-described second embodiment refers to the case that thecombination of the X-direction light-shielding sections 12 and theY-direction light-shielding sections 18 and 19 function correspond tothe “inter-pixel light-shielding sections”. However, the X-directionlight-shielding sections 12 need to be used for the “frame area” that isplaced outside the effective display area and that surrounds theeffective display area.

LCD Device of Second Embodiment

A LCD device according to the second embodiment of the inventioncomprises the above-described color filter of the second embodiment andthe TFT substrate 26 (see FIGS. 16, 17, 18A, and 18B) used in the firstembodiment. This LCD device is designed to operate in the normally blackmode. In this device, desired light-shielding sections can be realizedusing the red and blue color layers 1a and 2a having simpler patternsthan the first embodiment, and necessary and sufficient light-shieldingperformance can be realized.

Since the TFT substrate 26 comprises the field-shielding sections 46a ofthe common electrodes 46 that shield the leaked electric field, theamount of the leaked electric field is decreased and as a result,backlight leakage due to defective orientation of liquid-crystalmolecules is suppressed or avoided. Moreover, the TFT substrate 26 has astructure that makes it possible to shield the backlight with the datalines 50, the common electrode lines 43 and the scanning lines 49 bymaking these lines 50, 43 and 49 of opaque metal films. Thus, even ifthe Y-direction light-shielding sections of the color filter are formedby the overlapped parts of any two adjacent color layers, sufficientlight-shielding performance for the external light is obtainable.

For example, with the Y-direction light-shielding sections comprisingthe red and green color layers 1a and 3a, the OD value lowers. However,the reflected light of the external light by the wiring lines (e.g., thedata lines 50) on the TFT substrate 26 penetrates through the saidY-direction light-shielding sections twice. Therefore, even if thelight-shielding sections comprise the red and green color layers 1a and3a, sufficient light-shielding effect is obtained and no display qualitydegradation is seen. However, the TFTs 51 are provided near the scanninglines 49. Thus, to suppress the leakage current of the TFTs 51 inducedby light irradiation, it is necessary for the Y-directionlight-shielding sections to include the color layer (here, the red colorlayer 1a) that shields the light of particular wavelength giving largeeffect to the leakage current.

On the other hand, since unshielded regions that are not shielded bymetal wiring lines exist near the scanning lines 49, high OD values arenecessary. Therefore, with the X-direction light-shielding sections 12for shielding the vicinities of the scanning lines 49 that necessitatehigh OD values, the combination of the red and blue color layers la and2a that minimizes the transmittance is required.

With the LCD device according to the second embodiment using theabove-described color filter of the second embodiment, the combinationof the red and blue color layers la and 2a that minimizes thetransmittance of light is used for the X-direction light-shieldingsections 12. At the same time, the combination of two adjoining ones ofthe red, blue, and green color layers 1a, 2a and 3a is used for theY-direction light-shielding sections 18 and 19 that require not so highOD values. Therefore, compared with the first embodiment where thecombination of the red and blue color layers 1 and 2 is used for theentire effective display region, the patterns of the red and blue colorlayers 1a and 2a can be made simpler while keeping necessary andsufficient light-shielding performance for the LCD device.

Moreover, since the color filter of the second embodiment is used, thereis an advantage that high contrast and good color reproductivity can beobtained without a black matrix and that the response characteristicsare fast.

LCD Device of Third Embodiment

A LCD device according to a third embodiment of the invention comprisesthe above-described color filter of the first embodiment and the TFTsubstrate 26a shown in FIGS. 22, 23A, and 23B, forming the structureshown in FIG. 17. The TFT substrate 26a is approximately the samestructure as that shown in FIG. 4 of the Japanese Non-Examined PatentPublication No. 2005-241923 cited in Background of the Invention.

The structure of the TFT substrate 26a is the same as the TFT substrate26 (see FIGS. 16, 17, and 18A and 18B) except that the common electrodes46′ have a different structure. Therefore, the explanation about thesame structure is omitted here by attaching the same reference symbolsto the corresponding elements and only the different points will beexplained below.

With the TFT substrate 26 used in the first embodiment, as seen fromFIG. 16, the common electrodes 46 are formed in such a way that thefield-shielding sections 46a of the electrodes 46 do not overlap withthe corresponding TFTs 51. On the other hand, with the TFT substrate 26aused in the second embodiment, as seen from FIGS. 22 and 23A, the commonelectrodes 46′ are formed in such a way that the field-shieldingsections 46a′ of the electrode 46′ overlap with the corresponding TFTs51. The field-shielding sections 46a′ prevent the leaked electric fieldfrom the scanning lines 49 and the data lines 50 from being applied tothe liquid-crystal layer 80. The sections 46a are patterned to overhangthe scanning and data lines 49 and 50 on the third interlayer insulatinglayer 64. By shielding the leaked electric field from the TFT substrate26 with the field-shielding sections 46a′, the amount of electrificationof the red, blue and green color layers 1a, 2a, and 3a can be decreased.Therefore, the defective orientation of liquid-crystal molecules (e.g.,disclination) is suppressed or avoided and as a result, display defectssuch as color irregularity can be prevented.

With the TFT substrate 26a, since the field-shielding sections 46a′overhang the TFTs 51, the field-shielding effect is higher than the TFTsubstrate 26 used in the first embodiment. On the other hand, there is ahigh possibility that the sections 46a′ gives a bad effect to theoperation characteristics of the TFTs 51 if the thickness of the secondand third interlayer insulating layers 63 and 64 fluctuates toward thesmaller side due to errors occurring during the fabrication processes.However, if no problem occurs about the safety margins for the operationcharacteristics of the LCD device, the TFT substrate 26a may be usedwithout any practical problems.

With the LCD device according to the third embodiment, the color filterof the first embodiment and the TFT substrate 26a shown in FIGS. 22, 23Aand 23B are used in combination. Moreover, the difference between theTFT substrates 26 and 26a is the above-described effect caused by thepattern difference of the field-shielding sections 46a′. Therefore, thesame advantages as those of the LCD device according to the firstembodiment are obtained.

LCD Device of Fourth Embodiment

A LCD device according to a fourth embodiment of the invention comprisesthe above-described color filter of the second embodiment and the TFTsubstrate 26a used in the third embodiment, forming the structure shownin FIG. 17.

With the LCD device according to the fourth embodiment, the color filterof the second embodiment and the TFT substrate 26a shown in FIGS. 22,23A and 23B are used in combination. Moreover, the difference betweenthe TFT substrates 26 and 26a is the above-described effect alone whichis caused by the pattern difference of the field-shielding sections46a′. Therefore, the it is apparent that same advantages as those of theLCD device according to the second embodiment are obtained.

Tests for Color Filters and LCD Devices of the Invention

The above-described color filters according to the first and secondembodiments and the above-described LCD devices according to the firstto fourth embodiments using the said filters were actually fabricatedand thereafter, their effects or advantages were confirmed. Thefollowing examples 1 to 4 correspond to the first to fourth embodimentsof the invention, respectively.

EXAMPLE 1

First, a red-colored composite (which was generated by dispersing a redpigment in a transparent resin along with an optical initiator, apolymeric monomer, and a solvent) was coated on the surface of the glassplate 9 (the glass plate 71) to have a predetermined thickness with aspin coater. Then, the red-colored composite film thus formed wassubject to a reduced-pressure drying process and a pre-bake process.Thereafter, the said film was selectively exposed using a photomask andthen, was subjected to a developing process, a cleaning process withwater, and a post-bake process, forming the red color layer 1 having thepattern of FIG. 8A.

Following this, in the same way as the red color layer 1 using ablue-colored composite, the blue color layer 2 having the pattern ofFIG. 8B was formed to be overlapped with the red color layer 1.

Finally, in the same way as the red color layer 1 using a green-coloredcomposite, the green color layer 3 having the pattern of FIG. 8C wasformed to be overlapped with the blue color layer 2.

In this way, the color filter 72 having the red, blue and green pixelsand the two-layered light-shielding sections 12 comprising the red andblue color layers 1 and 2 was obtained. The formation order of the redand blue color layers 1 and 2 may be reversed. At this stage, the leveldifference “f” on the green pixel (the green pixel formation section 3G)in FIG. 12B was 2.0 to 2.5 μm.

In addition, regarding the various alignment markers formed on theopposite substrate 70 simultaneously with the color filter 72, thepatterned blue color layer 2 formed solely and/or the two-layeredpatterned blue and red color layers 2 and 1 were used. This was toensure the recognizability of monochromatic cameras frequently used forvarious processes and laser sensors for the wavelength of approximately600 nm.

Subsequently, the overlapped parts (protruding parts) 10 of the greencolor layer 3 on the light-shielding sections 12 were removed bypolishing the entire surface of the glass plate 9. At this stage, thethicknesses of the red, blue, and green color layers 1, 2, and 3 in thepixels were 2.0 μm, 2.0 μm, and 2.0 μm, respectively. The chromaticityof the respective color layers 1, 2, and 3 were adjusted to satisfy theEBU standard.

Furthermore, a liquid of transparent thermosetting resin was coated onthe whole surface of the color filter using a spin coater to form atransparent thermosetting resin film. The film was cured in an oven toform the overcoat layer 23 (73). The thickness of the overcoat layer 23(73) was approximately 1.0 μm. At this stage, the level difference “f”(see FIG. 12B) on the green pixel (the green pixel formation section 3G)was approximately 1.5 μm.

Thereafter, on the overcoat layer 23 (73) thus formed, a photosensitiveresin was coated with a spin coater to form a photosensitive resin film.Next, this film was subjected to a reduced-pressure drying process and apre-bake process. Then, this film was selectively exposed using aphotomask and was subjected to a developing process, a cleaning processwith water, and a post-bake process, forming the photo spacers 20 (81).At this stage, by adjusting the height of the spacers 20 (81), the cellgap was set at 3.0 μm. These spacers 20 (81), which have the shape shownin FIGS. 13A and 13B, were located to be overlapped with the green colorlayer 3 on the light-shielding sections 12. In this way, the oppositesubstrate 70 on which the color filter 72 of the first embodiment wasmounted was obtained.

The arrangement of the photo spacers 20 may be changed to the positionsoverlapped with the red or blue color layer 1 or 2 over thelight-shielding sections 12 as necessary. Moreover, the photo spacers 20may be placed at the positions overlapped with two of the red, blue andgreen color layers 1, 2 and 3 over the light-shielding sections 12 or atthe positions overlapped with all the color layers 1, 2 and 3.

On the other hand, the TFT substrate 26 shown in FIG. 16 was formed inthe following way.

First, a metal film (e.g., Cr film or Al alloy film) was deposited onthe transparent plate 61 and then, the metal film was patterned to formthe scanning lines 49 and the common electrode lines 43. Next, on themetal film thus patterned, a silicon nitride layer was formed as thefirst interlayer insulating layer 62, where the first interlayerinsulating layer 62 serves as the gate insulating films. Thus, thescanning lines 49 and the common electrode lines 43 were covered withthe first interlayer insulating layer 62.

Next, on the first interlayer insulating layer 62, an a-Si film and ann-type a-Si film were successively deposited and patterned, forming thea-Si film 54. A metal film (e.g., Cr film or Al alloy film) was thenformed on the first interlayer insulating layer 62 and was patterned toform the pixel auxiliary electrodes 56, the data lines 50 and the drainand source electrodes 53 and 53 of the TFTs 51.

Thereafter, the structure thus formed was covered with an insulatingfilm made of an organic resin, inorganic silicon nitride or the like asthe second interlayer insulating layer 63. Then, an insulating film madeof an organic resin, inorganic silicon nitride or the like as the thirdinterlayer insulating layer 64 was formed on the second interlayerinsulating layer 63.

The second and third interlayer insulating layers 63 and 64 wereselectively etched to form the contact holes 48 for the pixel electrodes47, where the contact holes 48 reach the corresponding pixel electrodes47 and the source electrodes 52. The first, second and third interlayerinsulating layers 62, 63 and 64 were selectively etched to form thecontact holes 45 for the common electrodes 46, where the contact holes45 reach the corresponding common electrodes 46 and the common electrodelines 43.

Furthermore, a transparent conductive film such as ITO was formed on thethird interlayer insulating layer 64 and patterned, forming the pixelelectrodes 47 and the common electrodes 46. At this stage, the pixelelectrodes 47 were electrically connected to the corresponding pixel andsource electrodes 47 and 52 by way of the corresponding contact holes48. The common electrodes 46 were electrically connected to thecorresponding common electrode lines 43 by way of the correspondingcontact holes 45.

In this way, the TFT substrate 26 with the structure of FIG. 16 wasobtained.

On the inner surfaces of the opposite substrate 70 (on which the colorfilter of the first embodiment was mounted) and the TFT substrate 26,alignment layers 74 and 65 were respectively formed by coating. Rubbingprocess was applied to the alignment layer 65 in such a way that therubbing direction for the TFT substrate 26 (i.e., the initial alignmentdirection of the liquid-crystal molecules) accorded with thelongitudinal direction of the pixel electrodes 47 (i.e., the directionof the arrow in FIG. 16). Similar rubbing process was applied to thealignment layer 74.

After a sealing material was coated on the peripheries of the substrates70 and 26, the substrates 70 and 26 were coupled. A liquid crystal wasinjected into the gap between the substrates 70 and 26 and thereafter,the gap was sealed with the sealing material. At this stage, theliquid-crystal layer 80 was formed between the substrates 70 and 26. Thecell gap was set at 3.0 μm.

If the liquid crystal is injected into the gap by the known droppingmethod, after a sealing material is coated on the peripheries of thesubstrates 70 and 26, a liquid crystal is dropped on the innersurface(s) of at least one of the substrates 70 and 26. Thereafter, thesubstrates 70 and 26 are coupled and the gap is sealed.

Subsequently, the polarizer plates 76 and 66 were attached to the outersurfaces of the opposite and TFT substrates 70 and 26, respectively.Wiring was carried out for the backlight module, the board for supplyingthe signals and the external power, or the like. Thus, the LCD devicewas fabricated.

EXAMPLE 2

First, a red-colored composite (which was generated by dispersing a redpigment in a transparent resin along with an optical initiator, apolymeric monomer, and a solvent) was coated on the surface of the glassplate 9 (the glass plate 71) to have a predetermined thickness with aspin coater. Then, the red-colored composite film was subject to areduced-pressure drying process and a pre-bake process. Thereafter, thefilm was selectively exposed using a photomask and then, was subjectedto a developing process, a cleaning process with water, and a post-bakeprocess, forming the red color layer la having the pattern of FIG. 19A.

Following this, in the same way as the red color layer la using ablue-colored composite, the blue color layer 2a having the pattern ofFIG. 19B was formed to be overlapped with the red color layer 1a.

Finally, in the same way as the red color layer la using a green-coloredcomposite, the green color layer 3a having the pattern of FIG. 19C wasformed to be overlapped with the blue color layer 2a.

In this way, the color filter 72 was obtained, which has the red, blueand green pixels, the X-direction light-shielding sections 12, thered-and-green Y-direction light-shielding sections 18, thegreen-and-blue Y-direction light-shielding sections 19, and theblue-and-red Y-direction light-shielding sections. The X-directionlight-shielding sections 12 were used for light-shielding thecorresponding regions to the scanning lines 49 on the TFT substrate 26a.The red-and-green, green-and-blue, and blue-and-red Y-directionlight-shielding sections 18 and 19 were used for light-shielding thecorresponding regions to the data lines 50 on the TFT substrate 26a. Theformation order of the red and blue color layers 1a and 2a may bereversed.

The X-direction light-shielding sections 12 had the two-layer structurecomprising the red and blue color layers 1a and 2a. The red-and-greenY-direction light-shielding sections 18 had the two-layer structurecomprising the red and green color layers 1a and 3a. The green-and-blueY-direction light-shielding sections 19 had the two-layer structurecomprising the green and blue color layers 3a and 2a. The blue-and-redY-direction light-shielding sections had the two-layer structurecomprising the blue and red color layers 2a and 1a.

Subsequently, the overlapped parts (protruding parts) 10 of the greencolor layer 3a on the two-layered X-direction light-shielding sections12 comprising the red and blue color layers 1a and 2a were removed bypolishing the entire surface of the glass plate 9. At this stage, thethicknesses of the red, blue, and green color layers 1a, 2a, and 3a inthe pixels were 2.0 μm, 2.0 μm, and 2.0 μm, respectively. Thechromaticity of the respective color layers 1a, 2a, and 3a was adjustedto satisfy the EBU standard.

Furthermore, a liquid of transparent thermosetting resin was coated onthe whole surface of the color filter using a spin coater to form atransparent thermosetting resin film. The film was cured in an oven toform the overcoat layer 23 (73). The thickness of the overcoat layer 23(73) was approximately 1.0 μm. At this stage, the level difference “f”(see FIG. 13B) on the green pixel (the green pixel formation section3Ga) was approximately 1.0 μm.

Thereafter, on the overcoat layer 23 (73) thus formed, a photosensitiveresin was coated with a spin coater to form a photosensitive resin film.Next, this film was subjected to a reduced-pressure drying process and apre-bake process. Then, this film was selectively exposed using aphotomask and was subjected to a developing process, a cleaning processwith water, and a post-bake process, forming the photo spacers 20 (81).At this stage, by adjusting the height of the spacers 20 (81), the cellgap was set at 3.0 μm.

On the inner surfaces of the opposite substrate 70 (on which the colorfilter of the example 1 was mounted) fabricated in the above-mentionedway and the TFT substrate 26 fabricated in the same way as the example1, alignment layers 74 and 65 were respectively formed by coating.Similar rubbing processes to the example 1 were applied to the alignmentlayers 74 and 65.

After a sealing material was coated on the peripheries of the substrates70 and 26, the substrates 70 and 26 were coupled. A liquid crystal wasinjected into the gap between the substrates 70 and 26 and thereafter,the gap was sealed with the sealing material. The cell gap was set at3.0 μm.

Subsequently, the polarizer plates 76 and 66 were attached to the outersurfaces of the opposite and TFT substrates 70 and 26, respectively.Wiring was carried out for the backlight module, the board for supplyingthe signals and the external power, or the like. Thus, the LCD devicewas fabricated.

EXAMPLE 3

The opposite substrate 70 (on which the color filter of the example 1was mounted) fabricated in the same way as the example 1 and the TFTsubstrate 26a fabricated in the same way as the third embodiment werecoupled. A liquid crystal was injected into the gap between thesubstrates 70 and 26a and thereafter, the gap was sealed with thesealing material. The cell gap was set at 3.0 μm. Thereafter, the LCDdevice was obtained through the same process steps as those of theexample 1.

EXAMPLE 4

The opposite substrate 70 (on which the color filter of the example 2was mounted) fabricated in the same way as the example 2 and the TFTsubstrate 26a fabricated in the same way as the third embodiment werecoupled. A liquid crystal was injected into the gap between thesubstrates 70 and 26a and thereafter, the gap was sealed with thesealing material. The cell gap was set at 3.0 μm. Thereafter, the LCDdevice was obtained through the same process steps as those of theexample 2.

COMPARATIVE EXAMPLE 1

Using the red, blue, and green color layers 101, 102 and 103 shown inFIGS. 1A, 1B and 1C, the prior-art color filter of FIG. 2 was fabricatedthrough the method described in BACKGROUND OF THE INVENTION.

With this prior-art color filter, the light-shielding sections 133 hadthe three-layer structure comprising the red, blue and green colorlayers 101, 102 and 103, and the light-shielding sections 133a had thetwo-layer structure comprising the red and blue color layers 101 and102. The thicknesses of the red, blue, and green color layers 101, 102,and 103 in the pixels were 2.0 μm, 2.0 μm, and 2.0 μm, respectively. Thethickness of the overcoat layer 123 was approximately 1.0 μm. The leveldifference “h” (see FIG. 3A) on the green pixels (the green pixelformation sections 103G) was approximately 2.5 μm. The height of thephoto spacers 120 (81) was adjusted in such a way that the cell gap was3.0 μm. The photo spacers 120 (81) were arranged on the light-shieldingsections 133 to be overlapped with the green color layers 103, as shownin FIG. 2.

The opposite substrate was fabricated using the prior-art color filterthus fabricated and thereafter, it was coupled with the prior-art TFTsubstrate shown in FIG. 7 (where the common electrodes 146 do not havethe field-shielding sections for shielding the leaked electric fieldfrom the TFTs 151). In this way, the prior-art LCD device wasfabricated.

COMPARATIVE EXAMPLE 2

Using the red, blue, and green color layers 101, 102 and 103 shown inFIGS. 1A, 1B and 1C, the prior-art color filter of FIG. 4A wasfabricated through the method described in BACKGROUND OF THE INVENTION.

With this prior-art color filter, the light-shielding sections 133 hadthe three-layer structure comprising the red, blue and green colorlayers 101, 102 and 103, and the light-shielding sections 133a had thetwo-layer structure comprising the red and blue color layers 101 and102. The thicknesses of the red, blue, and green color layers 101, 102,and 103 in the pixels were 2.0 μm, 2.0 μm, and 2.0 μm, respectively. Thethickness of the overcoat layer 123 was approximately 1.0 μm. The leveldifference “i” (see FIG. 5A) on the blue pixels (the blue pixelformation sections 102B) was approximately 1.0 μm. The level difference“j” (see FIG. 6A) on the green pixels (the green pixel formationsections 103G) was approximately 2.5 μm. The height of the photo spacers120 (81) was adjusted in such a way that the cell gap was 3.0 μm. Thephoto spacers 120 (81) were arranged on the two-layered light-shieldingsections 133a to be overlapped with the blue color layers 102, as shownin FIG. 4A.

The opposite substrate was fabricated using the above-describedprior-art color filter and thereafter, it was coupled with the prior-artTFT substrate shown in FIG. 7 (where the common electrodes 146 do nothave the field-shielding sections for shielding the leaked electricfield from the TFTs 151). In this way, the prior-art LCD device wasfabricated.

Evaluation

The evaluation results for the above-described examples 1 to 4 and theabove-described comparative examples 1 and 2 are shown in Table 1 below.

TABLE 1 CONTRAST CELL GAP & LEVEL UNEVENNESS JUDGMENT EXAMPLE 1 2 2 ◯EXAMPLE 2 3 1 ◯ EXAMPLE 3 1 2 ◯ EXAMPLE 4 2 1 ◯ COMPARATIVE 5 4 XEXAMPLE 1 COMPARATIVE 5 5 X EXAMPLE 2

The “contrast level” and “cell gap & unevenness” in TABLE 1 wereevaluated according to the five-grade system from 1 to 5, where Level 1is the best. The “JUDGMENT” in TABLE 1 was evaluated according to thetwo-grade system, where “◯” means that the display quality is good while“X” means that the display quality is not good (bad).

Regarding the examples 1 to 4, the evaluation results for both “contrastlevel” and “cell gap & unevenness” were the best or near the best. Thismeans that no problem occurred for the display quality.

With the color filters of the examples 2 and 4, not only the leveldifference on the green pixels was reduced but also the said leveldifference was eliminated by surface polishing.

With the LCD devices of the examples 1 to 4, it was confirmed thatsufficient light-shielding performance was realized without damaging thecell gap formation.

Regarding the comparative example 1, the level difference “h” (see FIGS.3A and 3B) on the green pixels was extremely large. Moreover, since thephoto spacers 120 were arranged on the three-layered light-shieldingsections 133, the height of the spacers 120 was extremely small due tothe excessive difference “h”. As a result, local gap defects were likelyto occur.

Regarding the comparative example 2, the level difference “j” (see FIGS.6A and 6B) on the green pixels was approximately 2.5 μm. Since the cellgap was 3.0 μm, the gap “e” on the light-shielding sections 133 wasapproximately 0.5 μm, which means that the opposite substrate nearlycontacted the TFT substrate. Moreover, since the gap “e” on thelight-shielding sections 133 was as small as approximately 0.5 μm,foreign objects were likely to be caught in such the narrowed gap.

Variations

The above-described first to fourth embodiments are preferred embodiedexamples of the present invention. Therefore, it is needless to say thatthe present invention is not limited to these embodiments. Any othermodification is applicable to the embodiments.

For example, in the above-described embodiments of the invention, colorlayers of three primary colors (i.e., red, blue and green color layers)are used. However, the invention is not limited to this. Four or morecolor layers may be used, where other color layer(s) is/are added to thethree primary color layers. However, if the light-shielding sections areformed by the combination of the color layers that minimizes the opticaltransmittance, it is preferred that the level difference between thepixels adjacent to the light-shielding sections is smaller than the cellgap.

Moreover, in the above-described embodiments, the pixels are rectangularand arranged according to the stripe layout. However, the invention isnot limited to this. The shape of the pixels may be changed to any otherone. The arrangement or layout of the pixels may be the mosaic or deltaor the like.

While the preferred forms of the present invention have been described,it is to be understood that modifications will be apparent to thoseskilled in the art without departing from the spirit of the invention.The scope of the present invention, therefore, is to be determinedsolely by the following claims.

What is claimed is:
 1. A color filter, comprising: a transparentsupport; a first color layer formed on the transparent support, in aplan view, the first color layer having stripe-shaped first color pixelformation sections, second color pixel windows, and third color pixelwindows, which are arranged at predetermined intervals, respectively; asecond color layer formed to overlap with the first color layer, in theplan view, the second color layer having stripe-shaped second colorpixel formation sections, first color pixel windows, and third colorpixel windows, which are arranged at predetermined intervals,respectively; and, in the plan view, a third color layer havingisland-shaped third color pixel formation sections apart from eachother, wherein the first color pixel formation sections of the firstcolor layer are overlapped with the first color pixel windows of thesecond color layer, thereby defining first color pixels, and the secondcolor pixel formation sections of the second color layer are overlappedwith the second color pixel windows of the first color layer, therebydefining second color pixels, wherein the third color pixel formationsections of the third color layer are arranged in the third color pixelwindows of the first color layer and the third color pixel windows ofthe second color layer, the third color pixel windows of the first colorlayer being overlapped with the third color pixel windows of the secondcolor layer, thereby defining third color pixels, and wherein overlappedparts of the first color layer and the second color layer function aslight-shielding sections, and wherein peripheries of the third colorpixel formation sections are slightly overlapped with thelight-shielding sections and form protruding parts protruded above thelight-shielding sections, the protruding parts define inter-color partsto expose the light-shielding sections.
 2. The color filter according toclaim 1, wherein the first color pixel formation sections of the firstcolor layer are arranged along a first direction at predeterminedintervals and are extended along a second direction perpendicular to thefirst direction, and the second and third color pixel windows of thefirst color layer are defined by connection sections that connect thefirst color pixel formation sections adjacent to each other, and whereinthe second color pixel formation sections of the second color layer arearranged along the first direction at predetermined intervals and areextended along the second direction, and the first and third color pixelwindows of the second color layer are defined by connection sectionsthat connect the second color pixel formation sections adjacent to eachother.
 3. The color filter according to claim 1, wherein peripheries ofthe third color pixel formation sections are overlapped with thelight-shielding sections to have overlapped widths of 5.0 μm or less. 4.The color filter according to claim 3, further comprising spacersarranged to bury or fill the overlapped peripheries spaces defined bythe inter-color parts of the protruding parts of the third color pixelformation sections with the light shielding sections.
 5. The colorfilter according to claim 1, wherein peripheries of the third colorpixel formation sections are not overlapped with the light-shieldingsections.
 6. The color filter according to claim 5, further comprisingspacers arranged on the light-shielding sections.
 7. The color filteraccording to claim 1, wherein the first color layer comprises one of ared color layer and a blue color layer, and the second color layercomprises the other of the red color layer and the blue color layer. 8.The color filter according to claim 1, wherein the first color layer orthe second color layer comprises a red color layer.
 9. A liquid-crystaldisplay device comprising: a first substrate having the color filteraccording to claim 1; and a second substrate having active elements forswitching.
 10. The device according to claim 9, wherein the device isdesigned to operate in a normally black mode, wherein a common electrodeformed on the second substrate comprises shielding sections forshielding electric field leaked from the second substrate, and whereinthe shielding sections conduct their light-shielding operation invicinities of scanning lines formed on the second substrate.
 11. Thedevice according to claim 9, wherein first light shielding sections ofthe color filter are used for shielding light at corresponding locationsto scanning lines formed on the second substrate, and wherein secondlight-shielding sections of the color filter are used for shieldinglight at corresponding locations to data lines formed on the secondsubstrate.
 12. The device according to claim 9, wherein secondlight-shielding sections of the color filter are assigned to locationswhere backlight is shielded by wiring lines formed on the secondsubstrate, and wherein first light-shielding sections of the colorfilter are assigned to locations where backlight is not shielded bywiring lines formed on the second substrate.
 13. The color filteraccording to claim 1, wherein among the first color layer, the secondcolor layer, and the third color layer, only the third color layer hasisland-shaped color pixel formation sections.
 14. The color filteraccording to claim 1, wherein the overlapped parts of the first colorlayer and the second color layer form the light-shielding sectionswithout the third color layer.
 15. The color filter according to claim1, wherein the first color pixel formation sections of the first colorlayer are arranged along a first direction at predetermined intervalsand are extended along a second direction perpendicular to the firstdirection, and the second and third color pixel windows of the firstcolor layer are defined by connection sections that connect the firstcolor pixel formation sections adjacent to each other, wherein thesecond color pixel formation sections of the second color layer arearranged along the first direction at predetermined intervals and areextended along the second direction, and the first and third color pixelwindows of the second color layer are defined by connection sectionsthat connect the second color pixel formation sections adjacent to eachother, and wherein peripheries of the third color pixel formationsections are overlapped with the light-shielding sections to haveoverlapped widths of 5.0 μm or less.
 16. The color filter according toclaim 1, wherein the first color pixel formation sections of the firstcolor layer are arranged along a first direction at predeterminedintervals and are extended along a second direction perpendicular to thefirst direction, and the second and third color pixel windows of thefirst color layer are defined by connection sections that connect thefirst color pixel formation sections adjacent to each other, wherein thesecond color pixel formation sections of the second color layer arearranged along the first direction at predetermined intervals and areextended along the second direction, and the first and third color pixelwindows of the second color layer are defined by connection sectionsthat connect the second color pixel formation sections adjacent to eachother, and wherein the color filter further comprises spacers arrangedto bury or fill overlapped peripheries spaces defined by the inter-colorparts of the protruding parts of the third color pixel formationsections with the light shielding sections.
 17. A method of fabricatinga color filter, said method comprisin: forming a first color layer on atransparent support, in a plan view, the first color layer havingstripe-shaped first color pixel formation sections, second color pixelwindows, and third color pixel windows, which are arranged atpredetermined intervals, respectively; forming a second color layer tooverlap with the first color layer, in the plan view, the second colorlayer having stripe-shaped second color pixel formation sections, firstcolor pixel windows, and third color pixel windows, which are arrangedat predetermined intervals, respectively; and, in the plan view, forminga third color layer having island-shaped third color pixel formationsections apart from each other, wherein in the forming the second colorlayer, the first color pixel formation sections of the first color layerare overlapped with the first color pixel windows of the second colorlayer, thereby defining first color pixels, and the second color pixelformation sections of the second color layer are overlapped with thesecond color pixel windows of the first color layer, thereby definingsecond color pixels, wherein in the forming the third color layer, thethird color pixel formation sections of the third color layer arearranged in the third color pixel window of the first color layer andthe third color pixel windows of the second color layer, the third colorpixel windows of the first color layer being overlapped with the thirdcolor pixel windows of the second color layer, thereby defining thirdcolor pixels, and wherein overlapped parts of the first color layer andthe second color layer function as light-shielding sections, and whereinperipheries of the third color pixel formation sections are slightlyoverlapped with the light-shielding sections and form protruding partsprotruded above the light-shielding sections, the protruding partsdefine inter-color parts to expose the light-shielding sections.
 18. Themethod according to claim 17, wherein in forming the first color layer,the first color pixel formation sections of the first color layer arearranged along a first direction at predetermined intervals and areextended along a second direction perpendicular to the first direction,wherein the second color pixel windows and the third color pixel windowsof the first color layer are defined by connection sections that connectthe first color pixel formation sections thereof adjacent to each other,wherein in forming the second color layer, the second color pixelformation sections of the second color layer are arranged along thefirst direction at predetermined intervals and are extended along thesecond direction, and the first color pixel windows and the third colorpixel windows of the second color layer are defined by connectionsections that connect the second color pixel formation sections thereofadjacent to each other.
 19. The method according to claim 17, wherein inthe forming the third color layer, peripheries of the third color pixelformation sections are overlapped with the light shielding sections tohave overlapped widths of 5.0 μm or less.
 20. The method according toclaim 19, further comprising forming spacers in such a way as to bury orfill the overlapped peripheries spaces defined by the inter-color partsof the protruding parts of the third color pixel formation sections withthe light-shielding sections.
 21. The method according to claim 17,wherein after the forming the third color layer is completed, polishingthe third color layer is carried out to remove peripheries of the thirdcolor pixel formation sections placed on the light-shielding sections.22. The method according to claim 17, wherein the first color layercomprises one of a red color layer and a blue color layer, and thesecond color layer comprises the other of the red color layer and theblue color layer.
 23. The method according to claim 17, wherein thefirst color layer or the second color layer comprises a red color layer.24. The method according to claim 17, wherein among the first colorlayer, the second color layer, and the third color layer, only the thirdcolor layer has island-shaped color pixel formation sections.
 25. Themethod according to claim 17, wherein the overlapped parts of the firstcolor layer and the second color layer form the light-shielding sectionswithout the third color layer.
 26. A color filler, comprising: atransparent support: a first color layer formed on the transparentsupport, in a plan view, the first color layer having stripe-shapedfirst color pixel formation sections, second color pixel windows, andthird color pixel windows, which are arranged at predeterminedintervals, respectively; a second color layer formed to overlap with thefirst color layer, in the plan view, the second color layer havingstripe-shaped second color pixel formation sections, first color pixelwindows, and third color pixel windows, which are arranged atpredetermined intervals, respectively; and in the plan view, a thirdcolor layer having island-shaped third color pixel formation sectionsapart from each other, wherein the first color pixel formation sectionsof the first color layer are overlapped with the first color pixelwindows of the second color layer, thereby defining first color pixels,and the second color pixel formation sections of the second color layerare overlapped with the second color pixel windows of the first colorlayer, thereby defining second color pixels, wherein the third colorpixel formation sections of the third color layer are arranged in thethird color pixel windows of the first color layer and the third colorpixel windows of the second color layer, the third color pixel windowsof the first color layer being overlapped with the third color pixelwindows of the second color layer, thereby defining third color pixels,wherein overlapped parts of the first color layer and the second colorlayer function as light-shielding sections, wherein the first colorpixel formation sections of the first color layer are arranged along afirst direction at predetermined intervals and are extended along asecond direction perpendicular to the first direction, and the secondand third color pixel windows of the first color layer are defined byconnection sections that connect the first color pixel formationsections adjacent to each other, wherein the second color pixelformation sections of the second color layer are arranged along thefirst direction at predetermined intervals and are extended along thesecond direction, and the first and third color pixel windows of thesecond color layer are defined by connection sections that connect thesecond color pixel formation sections adjacent to each other, whereinperipheries of the third color pixel formation sections are slightlyoverlapped with the light-shielding sections and form protruding partsprotruded above the light-shielding sections, the protruding partsdefine inter-color parts to expose the light-shielding sections, whereinperipheries of the third color pixel formation sections are overlappedwith the light-shielding sections to have overlapped widths of 5.0 um orless, and wherein the third color pixel formation sections of the thirdcolor layer are arranged along the first and second directions at thepredetermined intervals, respectively.
 27. The color filter according toclaim 26, further comprising spacers arranged to bury or fill spacesdefined by the inter-color parts of the protruding parts of the thirdcolor pixel formation sections with the light shielding sections. 28.The color filter according to claim 26, wherein the first color layercomprises one of a red color layer and a blue color layer, and thesecond color layer comprises the other of the red color layer and theblue color layer.
 29. The color filter according to claim 26, whereinthe first color layer or the second color layer comprises a red colorlayer.
 30. A color filter, comprising: a transparent support; a firstcolor layer formed on the transparent support, in a plan view, the firstcolor layer having stripe-shaped first color pixel formation sections,second color pixel windows, and third color pixel windows, which arearranged at predetermined intervals, respectively; a second color layerformed to overlap with the first color layer, in the plan view, thesecond color layer having stripe-shaped second color pixel formationsections, first color pixel windows, and third color pixel windows,which are arranged at predetermined intervals, respectively; and in theplan view, a third color layer having island-shaped third color pixelformation sections apart from each other, wherein the first color pixelformation sections of the first color layer are overlapped with thefirst color pixel windows of the second color layer, thereby definingfirst color pixels, and the second color pixel formation sections of thesecond color layer are overlapped with the second color pixel windows ofthe first color layer, thereby defining second color pixels, wherein thethird color pixel formation sections of the third color layer arearranged in the third color pixel windows of the first color layer andthe third color pixel windows of the second color layer, the third colorpixel windows of the first color layer being overlapped with the thirdcolor pixel windows of the second color layer, thereby defining thirdcolor pixels, wherein overlapped parts of the first color layer and thesecond color layer function as light-shielding sections, wherein thefirst color pixel formation sections of the first color layer arearranged along a first direction at predetermined intervals and areextended along a second direction perpendicular to the first direction,and the second and third color pixel windows of the first color layerare defined by connection sections that connect the first color pixelformation sections adjacent to each other, wherein the second colorpixel formation sections of the second color layer are arranged alongthe first direction at predetermined intervals and are extended alongthe second direction, and the first and third color pixel windows of thesecond color layer are defined by connection sections that connect thesecond color pixel formation sections adjacent to each other, whereinperipheries of the third color pixel formation sections are slightlyoverlapped with the light-shielding sections and form protruding partsprotruded above the light-shielding sections, the protruding partsdefine inter-color parts to expose the light-shielding sections, andwherein the third color pixel formation sections of the third colorlayer are arranged along the first and second directions at thepredetermined intervals, respectively.
 31. The color filter according toclaim 30, further comprising spacers arranged on the light-shieldingsections.